Coastal Staphylinidae (Coleoptera): A worldwide checklist, biogeography and natural history

Abstract We provide a list of the 392 described species of Staphylinidae confined to coastal habitats worldwide. The list is in taxonomic sequence by subfamily, tribe, and genus and includes 91 genera. We provide the page reference of the original description of every species and genus listed and of many synonyms. We note the existence of recent reviews, phylogenies and keys of each of the tribes and genera included. Coastal Staphylinidae contain eight subfamilies: Microsilphinae, Omaliinae, Pselaphinae, Aleocharinae, Oxytelinae, Scydmaeninae, Paederinae, and Staphylininae. By ‘coastal habitats’ we mean habitats existing on the sea coast and subject to inundation or at least splashing by the very highest tides. This includes rocky, boulder, coral, sandy, and muddy seashores, and at least portions of salt-marshes, estuaries, and mangrove swamps. We exclude the sand dune habitat and higher parts of sea-cliffs. The list notes distribution of all the species, first according to the ocean or sea on whose shores it has been recorded, and second by country (and for the larger countries by province or state). Although this distribution is undoubtedly incomplete, it provides a basis for future development of a dedicated database. The ‘Habitats, Habits, and Classificatory Notes’ section is designed to provide ecologists with further taxonomic and ecological information. It includes references to descriptions of the immature stages, behavior of adults and immatures, their food, natural enemies, and habitat. We would have preferred to separate these entities, but current knowledge of ecology is developed in few instances beyond natural history. The Pacific Ocean basin was the origin and contributed to the dispersal of the majority of specialist coastal Staphylinidae at the level of genus. However, at the level of species, species belonging to non-coastal-specialist genera are about as likely to occur on the shores of other oceans as on the shores of the Pacific. This difference is a reflection of the antiquity of coastal genera and species. A complete bibliography, and habitat and habitus photographs of some representative coastal Staphylinidae species are provided.


introduction
We struggled to find an appropriate title for this work, but eventually rejected the expressions intertidal, marine, littoral, and seashore, all of which have been used by other authors. By "coastal" we mean species that dwell on sea coasts and are restricted to such habitats. However, we restrict the definition to habitats to those that are normally or occasionally inundated by tides, excluding cliff and dune habitats, as well as inland salt-laden habitats. Thus, those species included dwell in the intertidal zone and at the drift line, and in mangrove swamps, salt marshes, and estuaries where they may be inundated by the tides. We do not employ the terms halophile and halobiont because they refer to organisms that dwell in salt-laden habitats, which are not restricted to coastal areas; indeed saline lakes and ponds occur hundreds of kilometers from coasts, and we do not wish to consider these.
A book chapter on intertidal Staphylinidae (Moore and Legner 1976) was undoubtedly Ian Moore's major contribution to this, his favorite, subject. Moore had already published numerous papers on intertidal Staphylinidae of the Pacific coast of North America. In this pioneering treatment he endeavored to summarize the world literature on intertidal staphylinids. To do so it was necessary to separate the literature on intertidal species from that on non-marine species with which it was intermixed. The task was daunting because of the number of species in the family (over 54,000 are now recognized), a huge polyglot literature, and the lack of habitat information in many of the early taxonomic publications. He included keys to identification of adults to the level of genus.
In the subsequent 35 years, some genera that Moore dealt with have been revised (see particularly studies by Ahn, Ashe, Assing, Gusarov, Haghebaert, Herman, Jeon, Klimaszewski, Maruyama, and Zerche), additional species have been described, synonymies have been reported, there has been much change in the higher classification of Staphylinidae, and there have been some studies of the behavior of intertidal Staphylinidae. These changes make an updated contribution worth undertaking. This contribution is not simply an updating of Moore and Legner (1976), but it additionally lists all the staphylinid species (not just genera) that are believed to be restricted to coastal habitats. This list is augmented by page-references to their original descriptions in the literature, to references to generic revisions, and to publications on behavior of the species in question. We believe this will enable interested readers to access the original literature more readily. In this contribution, however, we do not include keys to identification of adults. For these the reader is urged to consult the cited literature. This contribution is intended for the reader who is willing and able to tackle the taxonomic literature, even if the ultimate objective is ecological or ethological.
This contribution lists some 392 species, in 91 genera, of Staphylinidae that are believed to be confined to coastal habitats. Some genera are confined to coastal habitats. Others include species that are confined to coastal habitats (and primarily only those with such restricted habitat are included in this treatment). One large genus, Bledius Leach, is exceptional in that its members live on banks of either freshwater or saline water bodies. Among the latter group it is in many instances unclear whether they are restricted to marine saline habitats. Moore and Legner (1976) included not only genera that restricted to intertidal habitats, but also genera whose members had frequently or occasionally been found there. Our contribution is more selective in that it tries to admit only those species for which there is evidence of restriction to such habitats. This attempt to concentrate on true coastal species is emphasized by Smetana (2009) in his critical review of a paper published by Majka et al. (2008). Smetana's (2009) viewpoint is to exclude those species that are occasional or even frequent visitors to the coastal habitat, and to concentrate on those that are confined to the habitat. There is some difficulty in treating members of the large genus Bledius because some species occupy not only coastal habitats, but also inland saline habitats; we attempt to exclude species that are not restricted to coastal habitats.
The current epitome of a study of regional coastal staphylinids is that by Hammond (2000). It discusses systematics and distribution of the British species, but it includes species that are not restricted to this habitat. The converse is perhaps Hasegawa and Kanie (1992) which provided a list of Staphylinidae collected at one seashore locality in a 2-year time period, making no distinction between those species restricted to seashores and those incidentally found there, and makes no mention of their wider distribution. Lengerken (1929) published an extensive compilation of the distribution of coastal species of the North, Baltic, Irish, Mediterranean, Black, and Caspian seas. Audisio and Taglianti (2010) presented a compilation of Coleoptera found on Italian coasts, but did not indicate which ones among the included species are restricted to such habitats.
The adjective halophilous seems first to have been used in English in the late 19 th century to mean plants that are salt-loving, or growing in salt marshes (OED 1971). Since then, a set of terms evolved to describe adaptations of organisms to saline environments: 1. Halobionts (obligate inhabitants of saline habitats), 2. Halophiles (facultative inhabitants of saline habitats), 3. Haloxenes (halotolerant species), 4. Incidentals (species not specifically associated with saline habitats but regularly found there. Such terms (in German) were used by Lengerken (1929) and other authors in English and French. We do not use these terms because they do not describe exactly what we want to include (and exclude), which is species that are restricted to sea coasts. We suppose that all of the species we list are halobionts, but we exclude halobionts living on the shores of inland saline lakes.

The checklist
This checklist is the first to attempt to enumerate all coastal staphylinids, and their distribution. Arrangement is taxonomic including subfamily, tribe, and genus; subtribes are included where defined. References to original generic and specific description are given. Generic and species synonyms are listed, each with original bibliographic reference. Listing of names of species within genera, genera within tribes, and tribes within subfamilies are mostly alphabetical, but names of subfamilies are arranged in taxonomic sequence. The arrangement followed for the higher categories is that of Lawrence and Newton (2000), Newton and Thayer (2007), and Grebennikov and Newton (2009) (Fig. 1).
To the far right of the taxonomic entries for genera (and in one instance for a tribe) reference to recent taxonomic revisions and phylogenies and keys to identification of adults [e.g., rev. Ahn 1996a; phy. Ahn and Ashe 1996b; key Moore and Legner 1976] is given.
Because this work deals with coastal species, primary geographical entries are given according to the oceans and seas on which species are found. Secondary entries are the names of the countries they inhabit, and tertiary entries (if any) are the (mainly political) subunits of larger countries, or islands belonging to the former. Compression of this information into a checklist required the use of abbreviations, which are as follows:  Newton and Thayer (2007) and Grebennikov and Newton (2009). is the study of habitat and behavior, by which can be learned the kinds of limitations to population size. This kind of information is sketchy for most coastal staphylinids, and is hard to present in tabular form. Therefore, this section presents textual information for genera and species whose habitat and behavior are known. Although this information is fundamental to population dynamics, it is also useful for the purposes of zoogeography.
Works on seashores and their fauna at large have traditionally been published by marine biologists. If we wanted to learn about the identification of the fauna on European shores, we might consult Barrett and Yonge (1958) or its replacement (Hayward et al. 1996), but we would be disappointed in coverage of Staphylinidae. If we wanted to read about sandy beaches and their fauna, we might consult McLachlan and Brown (2006), or Little et al. (2009) for rocky shores, or Hogarth (2007) for mangroves and seagrasses. Although we might learn much about those environments, we would again be disappointed in coverage of Staphylinidae. Not until we consult Cheng (1976) for marine insects do we gain an appreciation that many staphylinid species dwell on seashores (the included chapter by Moore and Legner), or Morris et al. (1980) for intertidal invertebrates of California (the included chapter by Evans), or Sherwood et al. (2000) for British coastal invertebrates (the included chapter by Hammond). The fault, if there is one, is the slowness in development of comprehensive treatment by entomologists of coastal staphylinids, and that the groundwork (taxonomic and behavioral studies) may not be in publications that marine biologists usually consult.
Habitats of coastal staphylinids are drifted seaweed, the intertidal zone, sandy beaches, pebble beaches, rocky shores, muddy beaches and flats, salt marshes, and mangrove swamps (Figs 2-5), but these are not necessarily mutually exclusive. Staphylinidae are very often associated with plants and algae. These may be growing in estuaries (especially marshgrasses, such as Spartina), on rocky shores (green, brown, and red algae), or on sandy shores (diatoms). Or they may be plants or seagrasses (Thalassia, Zostera, etc.) torn loose and deposited on any of those shores. Few staphylinid studies have identified associated plants specifically or even generically. Often, the drifted seaweeds (i.e., seaweeds deposited onshore by the tide) are called 'wrack'. Backlund (1945) used the term to include not only the brown alga Fucus, but many other algae, and the sea-grass Zostera (a vascular plant) deposited onshore. Barrett and Yonge (1958), in contrast, referred to large brown algae including the genus Laminaria as 'kelp', confining the term 'wrack' to moderately sized brown algae including Pelvetia, Fucus, and Ascophyllum. They apply these terms to growing seaweed as well as to seaweed deposited onshore.  defined wrack as drifted kelp. We employ the term 'drifted seaweed' to all algae deposited on shorelines, and we distinguish sea-grasses and marsh-grasses.
Drifted seaweed may be ephemeral and sparse and greatly subject to drying, to deep and decomposing and more or less permanent depending upon location and tides. Backlund (1945) published an ecological study of drifted seaweed in more or less permanent beds on seashores in Sweden and Finland, including its insect inhabitants. Staphylinids may occupy the sand under sparse accretions of seaweed. In thick seaweed beds, staphylinids inhabit the seaweed together with other invertebrates. Organisms     that eat and decompose seaweed are more abundant, including amphipods (Crustacea) and seaweed flies (Diptera: Coelopidae), both fed upon by many predacious Staphylinidae, including Cafius spp. Amphipods (commonly called 'beach-hoppers' or 'beachfleas') are innocuous with respect to humans, but coelopids, (i.e., Coelopa spp.) are more problematic. "The flies normally pass their whole lives on the weed [and] are abundant in the wrack all the year around [and] their numbers are not appreciated until something makes them come out into the open [and] they may fly in a band, a little above the ground [and] occasionally they stray far inland [and] can be a great nuisance when large numbers… congregate in shops, garages, and particularly dry-cleaners' (Oldroyd 1965: 173-174)." By feeding on these flies, Cafius spp. and other staphylinids can be considered as beneficial species. Poleward movement of seaweed deposits and their coelopid inhabitants has been noted and attributed to global warming, and there is a suspicion that Laminaria is in decline and that Fucus is expected to decline in the future in the British Isles (Edward et al. 2007).
Rocky shores offer refuges for specialist staphylinids (those not found in other habitats) in crevices or empty barnacle shells that trap pockets of air. Such shorelines often support the growth of algae, and these algae exhibit zonation according to species (Jones 1968). Staphylinids likewise distribute themselves according to such zones where they find refuge among algal holdfasts (Jones 1968;Topp and Ring 1988b). Rocky shores not only provide a substrate for barnacles and living algae, with which some staphylinids are associated, but they also frequently include tidal pool habitats. Tidal pools are inhabited by a few staphylinids, e.g., Rothium. A few species such as Micralymma marinum (which is believed to prey on Collembola) attain higher elevations above sea level on rocky cliffs (Thayer 1985).
Coral reefs, even five km from the shoreline, are habitat for a species of Brachypronomaea ). Its food there remained unknown until the abundant Collembola present at one such site suggested a probable food source (Ahn et al. 2003). Off the coast of the Aru Islands in the Indonesian Archipelago, among coral polyps, Fauvel (1878a) found unusual staphylinids and described the genera Corallis and Polypea. Their food and way of life have not yet been determined.
Shores may be graded from solid rock to boulders, cobbles, pebbles, gravels, and sand, and even finer particles typical of mud flats, salt marshes, and mangrove swamps. All of those substrates have their complement of coastal Staphylinidae. Table 1 is our attempt to summarize information about habitats across all genera; it is incomplete because the available information is incomplete. We summarize existing information not just about habitats but also about behavior and physiology in the section on Habits, Habitats, and Classificatory Notes under the name of each genus.

OMALIINAE
Worldwide, there are about 117 genera of Omaliinae placed in seven tribes (Thayer 2005). Only the genera Crymus, Omaliomimus, Macralymma, and Giulianium seem entirely restricted to seashores. Some species within the genera Micralymma and Oma-lium seem restricted to seashores. All of the coastal species thus far described occur at high latitudes and not in the tropics.

APHAENOSTEMMINI
Giulianium includes three species, all of them found under debris below the high tide mark, of beaches of the North Pacific Ocean. Larvae are unknown and there is no known association with seaweed (Ahn and Ashe 1999).

OMALIINI
Crymus (= Arpediomimus) includes two species, C. antarcticus and C. kronii, both associated with seaweed on seashores (Steel 1964). The larva of C. kronii was described by Steel (1964). Hughes et al. (2004) pointed out the existence of this species in the intertidal zone, not just on the South Island of New Zealand, but also on the Antipodes, Auckland, and Campbell islands of New Zealand, and found that it is one of the hosts of Cucujomyces phycophilus Weir and Rossi (Ascomycetes: Laboulbeniales). Macralymma includes only one species, M. punctiventre Cameron, and it is precinctive ("endemic") to New Zealand. Cameron (1945c) found the specimen in the Broun collection, labeled 'Taieri Beach.' It is widespread on the South Island of New Zealand and also occurs on Chatham Island. It is found under rotting kelp on sandy beaches (Emberson 1998). Hughes et al. (2004) pointed out the existence of this species in the intertidal zone of the Antipodes Islands of New Zealand and found that is one of the hosts of Cucujomyces phycophilus.
Micralymma marinum adults and larvae inhabit cracks in rocks in the intertidal zone of rocky coastlines. Adults and larvae are predacious, but their prey range is uncertain (Thayer 1985), probably including Collembola. In Britain, adults overwinter and larvae develop during the summer months (Steel 1970), or adults and larvae overwinter (King et al. 1979). In the northeastern USA some of the beetles may overwinter as larvae (Thayer 1985). These apterous beetles tolerate immersion in seawater (Elliott et al. 1983). A second species, M. brevilingue Schiødte (1845: 377, syn. M. dicksoni Mäklin 1878 has similar habits but is not entirely restricted to seashores, being also found in damp moss near coasts (Steel 1958) so we do not list it. A third species, M. laticolle, was admitted by Motschulsky (1860), its describer, not to belong to the genus Micralymma, but has not yet been assigned to another genus (see also Steel 1958). A fourth species, M. caucasicum Melichar, is not coastal (Steel 1962).
Omaliomimus occurs only on seashores, and some species may be abundant in rotting seaweed (Steel 1964). The larva of O. venator was described by Steel (1964); Hughes et al. (2004) pointed out the existence of this species in the intertidal zone not just on the New Zealand mainland, but also on the Antipodes, Auckland, Campbell, Macquarie and Snares islands of New Zealand, and found that is one of the hosts of Cucujomyces phycophilus Weir and Rossi (Ascomycetes: Laboulbeniales). Emberson (1998) pointed out the existence of undescribed species of Omaliomimus from the Chatham Islands of New Zealand.
Omalium species occupy various habitats, and only some occur on seashores associated with drifted seaweed. Seashore species include the European O. laeviusculum, O. riparium, and O. rugulipenne, as well as the North American O. algarum. Backlund (1945) found O. laeviusculum exclusively in deep layers of seaweed beds, but O. riparium was also found in carrion. Mjöberg (1906) described the pupa of O. riparium, and noted that it took seven days to develop to the adult. Steel (1970) found that larvae of O. laeviusculum and O. riparium occur in the summer months in Britain, whereas Larsson and Gigha (1959) had reported larvae of the latter in the winter in Iceland. Populations of O. riparium inhabiting Mediterranean shores have smaller adults than do those from northern Europe and have been considered a distinct subspecies (O. riparium impar Mulsant & Rey). Omalium littorale Kraatz seems to be strictly a seashore species in northern Europe, but in southern Europe it has been reported from high altitudes far from the sea (Zanetti 1987), so is not included in the checklist.

PSELAPHINAE
Worldwide there are 1200 genera of Pselaphinae, and all are predacious (Thayer 2005). Seashores are a very minor part of their habitat range. The genus Physoplectus is known only from saline coastal habitats.

GONIACERITAE BRACHYGLUTINI
Berlara bella adults were collected in a mangrove forest in Singapore, but not in parts inundated by the tide (Tanokuchi 1989).
Brachygluta has at least 43 species, but just six of them, known from America north of Mexico, appear to be restricted to coastal habitats, all these on the Atlantic coast (Chandler 1997).
Briaraxis depressa, the only representative of this genus, is known only from "under rubbish or logs on the beach" in the circum-Caribbean regions (Chandler 1992(Chandler , 2002. Mangalobythus furcifer, M. acutifolius, and M. murphyi adults were all collected in mangrove forests in Singapore or Thailand, where adults were seen to be active on open ground at low tide (Tanokuchi 1989).
The genus Nisaxis appears to be entirely coastal. Nisaxis maritima is known only from coastal habitats in United States Gulf Coast States; other species have been found in coastal saline habitats and also in inland saline habitats (Chandler 1997).
Pedisinops regulus adults were collected in the intertidal zone and on a coral reef in Japan's Ryukyu Islands (Sawada 1991).
The genus Physoplectus is entirely coastal. Physoplectus vinsoni is known only from coastlines in Mauritius in the Indian Ocean, whereas P. reikoae, P. miyakei, and P. irritans are from Pacific coastlines.
Prosthecarthron sauteri, originally described from Taiwan, was found to be widespread on patches of halophilous grasses close to the sea in North Korea, on patches of a reed on mud in river estuaries in the Japanese mainland, in mangrove habitats in the Ryukyu Islands, and under stones on the muddy ground of a mangrove seashore in Vietnam (Nomura et al. 2006).

ALEOCHARINAE
Worldwide, over 1,151 genera of this subfamily have been described, but its true diversity is without doubt much greater (Thayer 2005). It now contains some 12,851 species, but Hammond (1975) postulated that it might contain as many as 100,000 species. The genera are currently distributed among 51 tribes whose relationships require much study. It contains many specialist seashore inhabitants, not only at the level of genus, but even (as currently defined) at the level of tribe. Nowhere else among the Staphylinidae have entire tribes specialized to inhabit coastal habitats.
Prepupae of Aleocharinae spin a silken cocoon in which they pupate; some earlier authors incorrectly supposed the dorsal abdominal gland to be the source of the silk, although that gland produces defensive chemicals; the cocoon is not a special adaptation to immersion in water (Frank and Thomas 1984a).

ALEOCHARINI
Aleochara, the type genus of this tribe, appears to be the only one with coastal representatives, and thus far 16 are known. Its larvae develop as ectoparasitoids of cyclorrhaphous dipteran pupae within the dipteran puparium. On sea beaches, such dipteran puparia are typically found in piles of decaying seaweed, but also in carrion. All eight members of the subgenus Emplenota are found associated with such materials on sea beaches in Europe, north Africa, Korea, Japan, and both coasts of North America (Klimaszewski 1984). Additionally, A. (Coprochara) sulcicollis is also found in such habitats on the Pacific coast of North America and Chile in the south Pacific; A. (Coprochara) squalithorax is found on the Pacific shores of Japan and Korea; and A. (Coprochara) salsipotens is found on the African shores of the Indian Ocean and the African shores of the south Atlantic. Other members of the subgenus Coprochara do not, or seldom, occupy beaches. Two species of the subgenus Polystomota (A. punctatella and A. grisea) occupy European shores of the North Atlantic. Aleochara punctatella has long been confused with A. grisea, so old records of A. grisea, doubtless including some in the checklist, are in doubt and need re-evaluation. Three members of the subgenus Triochara occupy Pacific shores of eastern Asia, no others are known, and the habitat of all three appears to be seaweed. Parasitoidism by A. (Emplenota) obscurella (as A. algarum) of a dipterous puparium [Orygma luctuosum Meigen (Diptera: Coelopidae)] was reported by Scott (1916), and then in greater detail by Scott (1920) Lesne and Mercier (1922) were able to rear a 2 nd instar of A. obscurella (as A. algarum) from Coelopa puparia and described and illustrated it. Paulian (1938b) reared A. obscurella (as A. algarum) from 'Fucella fucorum Haliday', which we suspect referred to Fucellia fucorum Fallén (Diptera: Anthomyiidae), and added further descriptions and sketches of parts of the larvae; Paulian (1941) also described the larvae without specifying the host. Cals (1964) encountered A. obscurella (as A. algarum) as a parasitoid of Coelopa frigida and illustrated the pharate adult within its host puparium. Because parasitoidism is the only known way of life among larvae of at least 20 species of Aleochara, it is thought that all species have this habit (Peschke and Fuldner 1977;Klimaszewski 1984). Adult Aleochara are predacious.

ATHETINI
Acticola falkandica is the sole representative of this genus. The type specimen was collected in December 1914 in seaweed at Port Stanley, Falkland Islands (Cameron 1944b).
Adota has three Nearctic representatives (A. colpophila, A. gnypetoides, and A. maritima) reported from seaweed stranded on Pacific shores, and three Palearctic species (A. madida, A. magnipennis, and A. ushio) from eastern Asia (Gusarov 2003b). In the British Isles, A. maritima was reported by Easton (1971, under the synonym of Atheta immigrans) as an adventive species. Thus all six species are known only as seashore inhabitants.
Atheta, at the time of the Coleopterorum Catalogus (Scheerpeltz 1934), was a generic name applied to many confused and disparate groups. Over the subsequent years monophyletic groups have been split off from it as distinct genera, but the task is not yet complete. The following six seashore species are still assigned to it, within several subgenera. Atheta novaescotiae, not assigned to a subgenus, is a salt-tolerant, coastal, beach-drift species known from Atlantic Canada (Klimaszewski et al. 2006). Atheta (Actophylla) varendorffiana is known from the North Sea coast of Germany. Atheta (Badura) ririkoae dwells on the coasts of Korea and Honshu, Japan, as does A.
(Badura) tokiokai (but this latter also on the coasts of Kyushu). Atheta (Datomicra) acadiensis, from Canadian Maritime Provinces, is typically found in dry beach-drift material at the top of the littoral zone, the material consisting of dead Ascophyllum nodosum (L.) and Fucus vesiculosus L. (Klimaszewski and Majka 2007). Finally, A. (Sipalatheta) algarum is found in seaweed on the coast of Hong Kong in the South China Sea (Pace 1999b).
Brundinia was initially described as Homalota meridionalis with "variety" marina by Mulsant and Rey (1853). The "variety" was later recognized as a valid species, and the generic name Brundinia was introduced later. This, or these, species (now B. meridionalis and B. marina) were initially reported from plant debris in a salt marsh at Hyères, on the Mediterranean coast of France. It or they (no others have been recognized) were later reported from similar habitats on the coasts of the North Atlantic, Irish, North, and Baltic seas. On the German shores of the Wadden Sea (separated by barrier islands from the North Sea), B. marina is a common species in the lower salt marsh, and it shows time-varying abundance within the elevational gradient (Irmler and Heller 2002).
Halobrecta has about seven described species which in the past have been much confused by entomologists leading to much synonymy. The species occurring on Mediterranean shores need review (Gusarov 2004). For this reason, H. halensis Mulsant and Rey is here listed as a distinct species. The specimens of Halobrecta flavipes reported by Pace (2000b) from Chaiten, Chile belong to H. algophila (Gusarov 2004). The specimens of Halobrecta flavipes reported from Inaccessible Island in the South Atlantic Ocean by Klimaszewski et al. (2002) belong to H. algophila (Gusarov 2004). Adults of Exatheta cingulata and E. consors were described by Cameron (1920) and stated to have been collected in fungi, but Sawada (1985) transferred E. cingulata to Halobrecta, and Sawada (1987) synonymized E. consors. Because fungi are rarely found on seashores, and because all other species of Halobrecta occur on seashores, not in fungi, Cameron's (1920) specimens may have been mislabeled. Halobrecta discipula was reported as a new species in Chile by Pace (1999a) who stated that it was found "in decaying vegetables (lettuces, onions)" near Valparaíso; if those vegetables had been dumped on a sea beach (not stated) near the port city of Valparaíso, they could have been used by the beetles as surrogates for drifted seaweed; see also comments under Myrmecopora uvida. Illustrations of the habitus and diagnostic structures of adult H. flavipes together with details about its habitat in New Brunswick are provided by Klimaszewski et al. (2008).
The synonymy of Halobrecta flavipes in the checklist follows Pope (1977) and Lott (2008) and differs from that given by Klimaszewski et al. (2002) following Bernhauer and Scheerpeltz (1926). Bernhauer and Scheerpeltz (1926) listed 'Aleochara elongatula Stephens' (1832) as a synonym of H. flavipes, but Stephens (1832) referred to Aleochara elongatula Gravenhorst which, if Stephens was correct in his identification, refers to what is now called Atheta (Philhygra) elongatula (Gravenhorst) or Philhygra elongatula, a species which is not closely related. Furthermore, the habitat specified by Stephens (1832) for this species ["not common: found occasion-ally within the metropolitan district" (of London)] does not seem a likely habitat for a species of Halobrecta. If 'Aleochara elongatula Stephens' really is a synonym, it is the senior name and should be listed first among synonyms; however, this is likely to be a misidentification by Stephens. Also, according to Bernhauer and Scheerpeltz (1926), Halobrecta atricilla (Scriba) 1866: 290 nec Erichson is a synonym of H. flavipes and is so ranked in the checklist. For unexplained reasons, Bernhauer and Scheerpeltz (1926) did not accept Scriba's (1866) redescription of H. atricilla (Erichson) as pertaining to that species.
Hydrosmecta subalgarum is the only species assigned to this genus and is reported to inhabit seashores. Four specimens, collected under seaweed on sand at Tai Long, Hong Kong, China, are the only known collection of this species (Pace 1999b).
Iotarphia is monotypic. Its single species, I. australis, is known from adult specimens collected in a "maritime habitat" from Rockdale near Sydney and from Illawarra, both in New South Wales, Australia (Cameron 1943).
Osakatheta is monotypic. The single species, O. yasukoae, is known only from adults collected under stones on tidal flats at river mouths on the eastern coast of Honshu, Japan's largest island, where their habitat is threatened by industrial development (Maruyama et al. 2008).
Pontomalota contains two species, P. opaca and P. terminalis, both of them known from the Pacific coast of North America. They inhabit the mid to upper littoral zone of fine-grained sandy beaches, covered by tides only once or twice each month and containing stranded seaweed. Adults appear to be most active at night or on heavily cloudy days. They may occasionally be very abundant with hundreds of individuals per m 2 . Whereas P. terminalis is known only from California, P. opaca is distributed from Alaska to Baja California and shows clinal variation in color with specimens black in the north to light brown in the south. Their immature stages are unknown (Ahn and Ashe 1992). Adults spend the daylight hours beneath driftwood or piles of stranded seaweed (Kincaid 1961b).
Psammopora contains only one species, P. delittlei; adults were detected on a sandy beach in Tasmania, Australia (Pace 2003).
Psammostiba is a genus containing five species, all from seashores in the northern Pacific, with two species in the Nearctic (P. comparabilis and P. kenaii) and three in the Palearctic (P. hilleri, P. jessoensis, and P. kamtschatica). Adults (the immature stages have not been reported) have been found in drifted seaweed (Gusarov 2003b).
Tarphiota has three species (T. geniculata, T. fucicola, and T. densa) confined to fine-grained sandy seashores of Pacific North America. They live in the mid-to upperintertidal zone containing decaying seaweed and covered by only one or two high tides monthly. Larvae are unknown (Ahn 1996b(Ahn , 1999. Thinusa contains only two species (T. fletcheri and T. maritima) that live in the intertidal zone of sandy beaches immersed daily by tides on the Pacific coast of North America (Moore and Legner 1977;Topp and Ring 1988a;Ahn 1997b). Adults are active at night (Kincaid 1961b).

DIGLOTTINI
Various genera have been removed to other tribes, leaving only the genera Diglotta and Paradiglotta.
Diglotta contains eight species, three (D. mersa, D. sinuaticollis, and D. littoralis) from the North Atlantic and adjacent seas (North, Irish, and Mediterranean), one (D. brasiliensis) from the South Atlantic, one (D. secqi) from the Red Sea, two (D. legneri and D. pacifica) from the North Pacific, and one (D. maritima) from the South Pacific. Lohse (1985), followed by Haghebaert (1991) confused the two European species of Diglotta; although this issue was resolved by Good (1998), distribution records of these two species are doubtless still confused. A larva, collected on the west coast of Denmark in June 1917 in association with adults of D. mersa, was described and illustrated by Kemner (1925). Of the two European species, D. sinuaticollis (as D. mersa) occupies the intertidal and supralittoral zone of sandy beaches, whereas D. mersa (as D. submarina) occurs mostly in salt and mud-marshes (Haghebaert 1991). The type locality of D. brasiliensis is the intertidal zone of an estuarine beach in the state of Paraná (Caron and Ribeiro-Costa 2008). The North American species occur on sandy beaches (Moore and Orth 1979a). The adults of the western Palaearctic and Brazilian species have 4 posterior tarsomeres whereas the North American and Pacific species have 5 tarsomeres (Haghebaert 1991;Caron and Ribeiro-Costa 2008;Klimaszewski et al. 2008). Illustrations of the habitus and diagnostic structures of adult D. mersa together with details about its habitat in New Brunswick are provided by Klimaszewski et al. (2008).
Paradiglotta, with its single species P. nunni Ashe and Ahn (2005) from New Zealand is not included in the present list because it has not been found on seashores, only inland.

FALAGRIINI
Falagriini are a tribe of about 30 genera worldwide, only two of which have coastal representatives. The species of America north of Mexico were revised by Hoebeke (1985). A cladistic analysis of the genera of America north of Mexico by Ahn and Ashe (1995) showed monophyly of Bryobiota together with Myrmecopora, setting them apart from other genera in this tribe, which needs further study including more terrestrial falagriines.
The two species of Bryobiota (B. bicolor and B. giulianii) inhabit sandy beaches of the Pacific coast of North America. They live in the upper littoral zone, which is covered by tides only once or twice each month and contains buried decaying seaweed (Topp and Ring 1988a;Ahn and Ashe 1995). Larvae and diet are unreported.
Myrmecopora is currently divided into three subgenera (Lamproxenusa, Paraxenusa, and Xenusa). Fourteen species of Myrmecopora have been reported from seashores. Four species assigned to subgenus Lamproxenusa (M. algarum, M. chinensis, M. reticulata, and M. rufescens) dwell on the shores of eastern Asia in seaweed on sandy beaches (Assing 1997b). One species assigned to Paraxenusa (M. laesa) is known from the Mediterranean Sea and the Canary Islands of the north Atlantic. Ten species assigned to Xenusa range from the shores of the Red, Black, and Mediterranean seas to the north Atlantic with its adjacent seas (Irish, North, and Baltic); one of these (M. maritima) is known only from Madeira and the Canary Islands, and one (M. bernhaueri) only from the Red Sea; additional species occupy other habitats. Myrmecopora tenuicornis (Küster) was treated as a synonym of M. laesa (Erichson) by Fauvel (1902) and subsequent authors. Assing (1997a) expressed misgivings about this synonymy but explained that the location of the type specimen of M. tenuicornis is unknown, so the synonymy cannot be resolved. Myrmecopora (Xenusa) uvida, a species widespread in the western Palaearctic, was newly reported as an adventive species in Chile by Pace (1999a) who stated that it was found "under decaying vegetable products (cauliflowers, cabbages, onions, etc.)" near Antofagasta; if those vegetables had been dumped on a sea beach (not stated) near the port city of Antofagasta, they could have been used by the beetles as surrogates for drifted seaweed; see also comments under Halobrecta discipula.

HOMALOTINI
Most genera and species of this tribe are not seashore inhabitants. Four genera, Heterota, Paractocharis, Pseudopasilia and Thinobiosus, are exclusively seashore species. Just one species of Linoglossa has been reported from coastal habitats. Two species of subgenus Halmaeusa Kiesenwetter (1877) 1925: 171) are omitted from the checklist because they are not strictly seashore species (Steel 1964).
Cameronium has two species in the Indian Ocean (C. flavipenne and C. gomyi), one in the Red Sea (C. obockianus), one in North Africa (C. liebmanni Scheerpeltz 1957a) and, remarkably, one in the Gulf of California (C. sonorensis). If the last is correctly assigned to genus, the dispersal of its ancestors to that locale would be surprising and not easily explicable; consequently, its placement should be reinvestigated. Cameronium liebmanni is known only from an inland freshwater lake in Algeria so we do not include it in the present compilation. In Somalia, C. flavipenne adults were trapped more abundantly in the wet season than in the dry season (Chelazzi et al. 1983).
Heterota is represented by ten species distributed from the East Sea (H. The distribution of the last of these extends from the Mediterranean to the west coasts of Europe and the Canary Islands, and more recently was discovered in southern and northwestern Florida (USA), Jamaica, and the Caribbean coast of Mexico (Frank and Thomas 1984b). There is no apparent reason to believe that movement of H. plumbea from Europe to the Canary Islands and then to the Caribbean was assisted by humans. Small, salt-tolerant, winged insects are among the most likely candidates to disperse westward naturally with assistance of trade winds at tropical and subtropical latitudes. An annotated catalog of the species is provided by Park et al. (2008). On a sandy beach in Somalia, H. pictipennis adults were trapped more abundantly in the wet season than in the dry season (Chelazzi et al. 1983).
Linoglossa murphyi adults were collected in a mangrove forest in Singapore (Sawada 1991), but there is no evidence that other species of the genus are halobionts.
Paractocharis is represented by three species. The first described was P. fucicola, from sandy beaches under seaweed at Changi, Singapore, in the South China Sea (Cameron 1917c). The others, P. deharvengi and P. orousseti, were both found at Puerto Galera on Mindoro, Philippines, in the Luzon Sea, in "lavages" (washings) on the beach (Pace 1990).
Pseudopasilia is represented only by P. testacea, found on the coasts of the North Atlantic (England and France), North Sea (Belgium and southeastern England), and western Mediterranean (southern France, Italy including Sardinia, Tunisia, and probably Croatia). For many years entomologists confused Arena tabida with P. testacea (Tronquet 2003). Tronquet (2003) also noted adults found under small stones in the littoral zone.
Thinobiosus salinus is known only from the shores of Sonora in the Gulf of Mexico, where specimens were found in seaweed on the edge of a tidal pool (Moore and Legner 1977). No other species have been assigned to this genus.

LIPAROCEPHALINI
All members of this tribe appear restricted to coastal habitats. It appears to be monophyletic, with relationships of its seven genera suggested as ((Baeostethus, Ianmoorea) (Paramblopusa ((Amblopusa, Halorhadinus) (Liparocephalus, Diaulota)))) by Ahn et al. (2010). Five of its genera appear restricted to the north Pacific Ocean (with adjoining Gulf of California and East Sea), and two to the south Pacific.
Amblopusa contains five species, all in the North Pacific, two of them (A. alaskana and A. brevipes) in North America, two (A. pacifica and A. hokkaidona) on Hokkaido in northern Japan, and one (A. magna) in the Far East of Russia. All of them inhabit the mid-littoral zone. A late instar of A. alaskana was described in detail by Ahn and Ashe (1996a). Amblopusa pacifica adults were collected in wrack at Akeshi, eastern Hokkaido, in August 1990 (Sawada 1991). Amblopusa magna adults were collected in piles of drifted seaweed on fine sand beaches at Ryazonovka near Slavyanka, Russia in June 1993.
Baeostethus has one species (B. chiltoni) that occupies rocky intertidal areas in the Antarctic islands of New Zealand. Adults, as is typical of Liparocephalini, are flightless; a late instar was described by Steel (1964) and by Leschen et al. (2002).
Diaulota densissima adults were found to be plentiful along the rocky alga-covered shores of Departure Bay (British Columbia, Canada), and larvae were found and illustrated; adults are flightless (Saunders 1928). Adults and larvae of D. vandykei, and adults and a few suspected larvae of D. densissima were obtained from cracks of rocks and under algae at Moss Beach (San Mateo County, California, USA) in January; brief descriptions and an illustration of the apex of the larval abdomen of both was provided by Chamberlin and Ferris (1929). Moore (1956b) added some diagnostic notes on the structures of larvae of D. densissima, D. fulviventris, D. vandykei, and D. harteri collected from beaches in California and Baja California (Mexico) and provided a key to identify them. Meyerdirk (1969) studied a population of D. fulviventris at La Jolla (California, USA) and found adults and larvae in June, August, September, and December 1968 with the number of beetles averaging 0.70 per cm 2 , increasing to 1.1 per cm 2 in March 1969. The range of the population extended from 0.76 to 1.83 m above mean low tide, exclusively in association with the acorn barnacle Chthamalus fissus Darwin (Thoracica: Chthamalidae). The barnacle provided refuge from wave force and currents. Beetle activity was highest at low tide, and ceased when the substrate became saturated with sea water. Laboratory observations showed no evidence of a circadian or tidal rhythm. Pupae were formed in silk-like cocoons within empty barnacle tests and cracks in rocks. Adults respired under water by means of cutaneous respiration, expanding their abdomen to expose more membranous area (between sclerotized plates) when they were submerged.
Halorhadinus is represented by three species inhabiting the littoral zone of boulder shores and sandy beaches where seaweed is stranded in Korea and Japan. Maruyama and Hayashi (2009) discussed the habitat of Halorhadinus in detail. Their immature stages are unknown (Ahn 2001).
Ianmoorea is represented by a single species, I. zealandica, detected under fine gravels in the intertidal region of Breaker Bay, Wellington, New Zealand (Ahn 2004(Ahn , 2006. Liparocephalus is represented by four species. Liparocephalus cordicollis adults (misidentified as those of L. brevipennis) were found to be plentiful along the rocky algacovered shores of Departure Bay (British Columbia, Canada), and larvae were found and illustrated. Adults are flightless. Placed on the surface of a dish containing water and algae, adults descended and moved among the plants under water. They were thought to carry a film of air trapped "in the hairs of the body." Oviposition and pupation were not obtained in the laboratory. In the laboratory, larvae ate pupae of the chironomid Telmatogeton Schiner, and some ate dead larvae of that genus and of Camptocladius Wulp. Adults were not observed to feed. The disappearance of algae from the rocks during the summer may account for disappearance of the beetles and their subsequent reappearance during the winter. The foregoing account by Saunders (1928) is confusing in that it is drawn from observations on both L. cordicollis and Diaulota densissima and sometimes makes no distinction between the two. Topp and Ring (1988b) reinvestigated, and found L. cordicollis between 0.2 and 2.0 m above lowest spring tide on rocky shores of Vancouver Island (British Columbia, Canada).
Adults and larvae can withstand submergence in seawater for > 2 weeks at 10 o C, and thus can withstand continuous inundation from one spring tide to the next, although submerged larvae cease feeding and growing and do not pupate. Eggs were deposited in rock crevices or between the thalli of algae. Prepupae of L. cordicollis spin silken cocoons incorporating plant fragments in which to pupate. Liparocephalus cordicollis adults, and a few larvae and pupae, were found at Moss Beach (San Mateo County, California, USA) in November and December (Chamberlin and Ferris 1929). The final instar was described and illustrated, and the pupa was stated to be formed within a cocoon. A brief redescription by Moore (1956b) of the larva failed to clarify which of the species (L. brevipennis or L. cordicollis) he was describing. Liparocephalus tokunagai adults and larvae were found abundantly on rocky shores between high and low tidemarks in the spring of the year. The adults were seen to devour amphipod crustaceans of the genus Gammarus Fabricius . The final instar of L. cordicollis was described and illustrated by Ahn (1997a) with diagnostic characters for larvae of L. brevipennis and L. tokunagai together with a key for identification of larvae.
Paramblopusa was named by Ahn and Ashe (1996a) as a new genus to contain P. borealis, transferred from Amblopusa and known from the Pacific coast of North America where specimens have been collected under rocks on tidal flats. Later, P. eoa was described from the Kuril Islands of Russia, on rocks below a cliff at Negodnaya Bay .

MYLLAENINI
Concepts of the tribe Myllaenini have changed radically in the past few years, and genera such as Bryothinusa and Rothium have been transferred to it from other tribes.
Brachypronomaea esakii adults were found on a coral reef five km off the coast of Ishigaki Island, one of the Ryukyu Islands of southern Japan. This reef is submerged for all but about two hours daily. Adults are apterous, and the food and immature stages are unknown (Esaki 1956). Later collections from Okinawa in March-May 2002 showed that the beetles occupied coral reefs having large populations of Collembola suggesting that the beetles are predatory on the springtails (Ahn et al. 2003). The second species assigned to this genus is B. sawadai, described from the Bay of St. Vincent in New Caledonia by  without further information on its habitat. The nomenclature is not totally straightforward because  equated Thalassopora [a genus he described  to include T. nosybiana from Madagascar, and T. marchemarchadi (the type species) from what is now Vietnam] with Brachypronomaea in a heading "Brachypronomaea (Thalassopora Jarr., 1959". Nowhere in the following text did he mention this was a newly proposed synonymy. However, the text included description of a new species, B. sawadai, together with mention of characters of "B. Marche-Marchadi" and "B. Esakii".  intent was clearly to synonymize Thalassopora with Brachypronomaea. We believe that , despite lack of discussion, made a formal synonymy of Thalassopora with Brachypronomaea thereby transferring both the species he had originally placed in Thalassopora. A revision of the four species (B. esakii, B. marchemarchadi, B. nosybiana, and B. sawadai) is necessary. The habitat of Thalassopora (now Brachypronomaea) nosybiana was described as in sand and rocks near the oceanographical station of Nosy Bé, Madagascar (Paulian 1959). Its final instar (recognized because it was with adults, not reared) was described and illustrated, its digestive tube being packed with unicellular algae (Paulian 1959).
Bryothinusa, with 30 described species, restricted to seashores and with no species from other habitats, has the greatest diversity of all genera of the coastal Aleocharinae. Twenty-four live on shores of the Pacific Ocean and its surrounding seas, two (B. madecassa and B. perexilis) on the shores of the Indian Ocean, and four (B. cameroni, B. peyerimhoffi, B. subtilissima, and B. testacea) on the shores of the Red Sea (one of these also found in the Mediterranean). None has been reported from the Atlantic Ocean. Revisions have been published by Pace (1986), , and . Adults of B. sakishimana were collected in a mangrove forest (Sawada 1991), and those of B. chengae at light . The larva of the Californian B. catalinae was described by Moore and Orth (1979b) who described its habitat as "a shallow reef which is exposed at low-water and under water at high tide ... largely a field of boulders two or three feet across with smaller stones and gravel in sand ... adults and larvae were found beneath and on the stones in an association with dense worm tubes, chitons, limpets, small abalones, flatworms, small crabs and brittle stars." Four species (B. gangjinensis, B. koreana, B. minuta, and B. nakanei) have been found on Korean shores .
Of the Bryothinusa species found in Hong Kong, the habitats were distinguished as follows by Moore and Legner (1971) and : (B. chani): "At low water they wander on the surface of the mud flat and at high tide they are under seawater by holding tightly to rocks and dead shells"; (B. sawadai): "Found among rock crevices and shells of barnacles and oysters. When burrowing in the sand never more than 1 cm deep. Can be found throughout the year."; (B. sinensis): "Found among rocks, wandering on sand or burrowing in the sand as deep as 36 cm. Seems to prefer a sandy beach. Can be found throughout the year."; (B. hongkongensis): "Found wandering on sand or burrowing in sand as deep as 36 cm from mid-tidal zone to low tidal zone. Specimens were found from February to April" ). Descriptions do not suggest that members of the genus are alike in sharing one kind of habitat. The habitat of B. fluenta was even more unusual: it was "beneath the surface of a fresh water stream a short distance from the seashore... [it] seems to have invaded a fresh water habitat directly from salt water" . Adults of four of the Hong Kong Bryothinusa species (B. chani, B. hongkongensis, B. sawadai, and B. sinensis) were apparently able to breathe by plastron respiration, to feed on decaying microcrustacea, to occupy the mid-intertidal zone (0.6-1.5 m above mean tide level), to spend their time mainly at 0-15 cm below the sand surface, to mate on the sand surface, to occupy sand of low organic content, and to be macropterous except for B. chani (Wong and Chan 1977). Larvae of these four remained below the sand surface. The larva of B. koreana was described by Jeon and Ahn (2009), making it only the second species of the genus so treated (with the larva identified by mitochondrial DNA).
Corallis polyporum adults were stated by Fauvel (1878a) to be "sous-marines" (submarine or aquatic in the sea) under coral polyps in March. They occur together with those of Polypea, both genera being monotypic (Fauvel 1878a).
Lautaea murphyi adults were collected under mangroves in intertidal mud flats. Their digestive tracts were filled with fragments of harpacticoid copepods (Sawada 1989a). The genus is monotypic.
Myllaena is a genus distributed worldwide whose members are typically found in freshwater habitats, such as on the banks of lakes and streams, and in swamps. However, the North American M. insipiens Casey seems to have been collected only at or very close to coasts of the Atlantic and Gulf of Mexico of the USA (Klimaszewski 1982a), and is provisionally included in this list. Myllaena leleupi Pace (1985) is excluded from the checklist because its type locality in the Galapagos Islands is 4 km from the coast, despite a later record in a coastal habitat (Klimaszewski and Peck 1998).
Polypea corallis adults were said to have been found in the ocean under coral polyps, in March, to occur with those of Corallis, and to be submarine (Fauvel 1878a). Klimaszewski (1982b) argued that Polypea seems to lack any structural modification for a submarine existence.
Rothium was first included in Myllaenini by Ahn and Ashe (1996c). Its six described species inhabit the Pacific (including Gulf of California) coasts of North and South America. The first to be described, R. sonorensis, was collected in the intertidal zone "from algae covered pitted ryolite" and from "a tide pool" (Moore and Legner 1977). Discovery of two further Mexican species, and three from parts of Ecuador (including the Galapagos Islands) and Peru yielded little more information about their habitats. The larva of M. sonorensis was described by Moore (1977) and subsequently redescribed in detail by Ahn and Ashe (1996c).

OXYPODINI
Seashore representatives of this large tribe belong to seem to be only four genera, all monotypic: Chilodera, Dasydera, Gyronotus, and Oreuryalea (Assing and Maruyama 2002).
Chilodera falklandica is known only from seaweed at Port Stanley in the Falkland Islands in the South Atlantic, where specimens were collected in December 1914 (Cameron 1944b).
Gyronotus rufipennis is known only from North Island, New Zealand (Broun 1880).
Oreuryalea watanabei is known from the Russian Far East and northern Japan, where it was detected among drifted seaweed and other debris on beaches. Four female specimens collected in July and September each had a single mature egg in its ovaries (Assing and Maruyama 2002).

PHYTOSINI
The relationships of the tribe are unclear, and it is not yet certain that the tribe is monophyletic. The four genera remaining in this tribe, after removal of others to Myllaenini etc., are Actocharis, Arena, Euphytosus, and Phytosus.
Actocharis contains only two European species, A. readingii and A. cassandrensis. Both occur on Mediterranean coasts, and the first also occurs on North Atlantic coasts of England and France.
Arena includes one European species (A. tabida) and another (A. fultoni) from New Zealand, a remarkable distribution if these placements are actually correct (A. fultoni needs re-evaluation). Arena tabida was for years confused by entomologists with Pseudopasilia testacea (Homalotini) but it has a narrower distribution on the Atlantic coast of northwestern France, with the coasts of England and Wales, Irish Sea coasts of England and Wales, and North Sea coasts of England, Scotland, Netherlands, Germany, and Denmark, and is associated with drifted Fucus (Tronquet 2003). Bernhauer (1922a) described specimens collected by Hans Sauter at Alikang in Taiwan under the name Phytosus (Paraphytosus) schenklingi. No information about its habitat was provided. However, the name Paraphytosus Bernhauer was preoccupied (by Paraphytosus Cameron 1917e). In 1926, the Coleopterorum Catalogus designated Euphytosus Bernhauer and Scheerpeltz as a replacement name (through objective synonymy) for Paraphytosus Bernhauer, with P. (Euphytosus) schenklingi as its type and only species. Haghebaert (1993) excluded Euphytosus from the genus Phytosus with the consequence that it was automatically raised to generic rank; in that same work, Haghebaert also suggested (he wrote that he planned a later publication on the subject) an unnecessary new name (Pseudophytosus) for Euphytosus, so Pseudophytosus is not a valid name.
Phytosus is currently divided into two subgenera. The typical subgenus has three species; P. spinifer in the North Atlantic and Baltic, Black, North, and Mediterranean seas; P. fenyesi on the Atlantic coast of Senegal; and P. caribeanus on the shores of Guadeloupe in the West Indies. All five members of subgenus Actosus dwell on coasts of the North Atlantic and/or adjacent seas (Mediterranean, Baltic, or North). The present checklist does not mention Phytosus atriceps C.O. Waterhouse (1875), from Kerguelen Island, redescribed and illustrated by him (1879). The species was made the type of a new genus, Antarctophytosus by Enderlein (1909). Unaware of that assignment, Cameron (1917b) reported its finding in seaweed on a sandy seashore in the Falkland Islands and made it the type of a new genus, Paraphytosus. Cameron (1917e) admitted that he had misidentified the specimens, and also that the generic name Antarctophytosus Enderlein had precedence over Paraphytosus. Steel (1964) considered the genera Antarctophytosus Enderlein (1909), Paraphytosus Cameron (1917b), and Austromalota Brèthes (1925) all to be synonyms of Halmaeusa Kiesenwetter (1877). Steel (1964) also found that none of the species of Halmaeusa is restricted to seashores.

Incertae sedis
Salinamexus has two species (S. browni and S. reticulatus) that occur on the shores of the Gulf of California and one (S. koreanus) in Korea. Adults are able to fly. All three appear to occur exclusively under boulders or seaweed on seashores; their immature stages are unknown . Ahn et al. (2010) showed that the genus was not a member of the Liparocephalini. Its phylogenetic position is uncertain.
Anotylus has about 350 species worldwide, most associated with forest leaf litter, decomposing organic matter such as dung and carrion, and in mammal or ant nests (Newton et al. 2001). However, the European A. maritimus appears to occupy only seashore habitats, where it lives among seaweed and other drifted debris. Anotylus speculifrons (Kraatz 1857: 862) is often found in coastal habitats in western Europe, but occurs also in eastern Europe far from seashores; consequently we do not include it.
Blediotrogus has about five known species in Australia, New Zealand, and the Chatham Islands, and they are frequently found on seashores, under moist high-tide beach wrack (Makranczy 2006).
Pareiobledius has three known species, from the Afrotropical region, whose characteristic habitat is on seashores, under kelp (Makranczy 2006).
Sartallus has only one species, the Australian S. signatus, with winged adults. That species "is common on our [?South Australian] sandy beaches, where it [the adult?] hides under the seaweed and rubbish and feeds chiefly upon dead barnacles" (Froggatt 1907).

THINOBIINI
This is the largest oxyteline tribe with about 20 genera worldwide (Newton et al. 2001). Carpelimus, with several hundred species, worldwide, is one of the two largest genera. Most Carpelimus species occupy freshwater habitats such as the shores of rivers and lakes, and in swamps. Moore and Legner (1974b) described the larva and pupa of C. debilis (Casey 1889a: 374) and noted that it occurs often in stranded seaweed on the Pacific shores of North America, but occupies other habitats as well (so we do not list it). On the shores of Zanzibar, C. lucidus was found in seaweed and there seems to be no other habitat information, so we list it (Cameron 1944a).
Bledius, with over 450 species worldwide, is the other large genus within the Thinobiini. Herman (1986) classifies it according to species groups (an ordering we follow in our checklist) rather than formal subgenera. Only some Bledius species dwell on seashores, and some of these also occur inland in saline habitats. We attempt to list only those species that do not occur also in inland saline habitats, resulting in the inclusion of 57 species names. We refer the reader to Herman (1986: 11-72) for an excellent overview of the natural history of the genus [including its predators and parasites (partially reviewed in Frank 1982Frank , 1985b]. Consequently herein we mention only a few other studies. Several Bledius species found on coasts have been studied in some detail and have been noted as coastal species. However, evidence suggests that these are not strictly coastal, so they are not included in the present checklist. We mention them in part lest the reader should think we overlooked them and in part because the references cited provide larval and/or behavioral descriptions that may prove useful in comparison with future larval descriptions of coastal species. Four  Krogerus (1925). Four Bledius species [B. spectabilis Kraatz, B. unicornis (Germar), B. furcatus (Olivier), and B. fuscicornis Cameron] from France have larval descriptions by Paulian (1938aPaulian ( , 1941. The larva of B. albonotatus Mäklin from California was described (as B. ornatus LeConte) by Moore and Legner (1974a). Notes on behavior and development of B. spectabilis were published by Paulian (1942). Detailed studies by Bro Larsen (1936,1951,1952) of beetles of some Danish salt marsh and dune habitats dealt with several Bledius species particularly B. spectabilis. More recently, the distribution, behavior, and physiology of B. spectabilis was studied in Norfolk, England (Evans et al. 1971;Wyatt 1982Wyatt , 1986Wyatt and Foster 1988). The latter show the remarkable development of subsocial behavior among Bledius in which adults care for their brood. They also illustrate the form of the tunnels in which the entrance is narrowed to a bottle-neck so that it is not easily flooded by the tide (and can be blocked by the adults within a few minutes) to trap oxygen inside. Included is information on oxygen consumption and the minute algae that are the food of adults and larvae.
Bledius fenyesi and B. monstratus dwell on the Pacific coasts of North America in decaying, sand-covered piles of seaweed (Herman 1986). Evans's (1980) claim that adults of B. monstratus are predacious requires verification given that other members of the genus feed on algae.
Bledius subniger dwells on the sandy shores of Ostvoorn (Netherlands) just below the high tide mark, tunneling within the topmost 5 cm of sand, and occurring at densities up to 500 per m 2 . It feeds on Chlorophyta, Cyanophyta, and Chrysophyta (dia-toms). It is very active at the end of June and the beginning of July, with individuals walking on the sand surface, followed by swarming for mating or dispersal (Hollander and van Etten 1974;Hollander 1983). These authors also discuss the habits of Bledius arenarius, which dwells in dunes above the beach and is thus excluded from our list of seashore staphylinids. Griffiths and Griffiths (1983) found that Bledius punctatissimus attained densities of up to 2,260 adults per m 2 on a sheltered marine beach at Pawley's Island (South Carolina, USA). Adults and larvae below the sand surface are regularly immersed by the tide. At low tide they emerged to form galleries just below the sand surface and fed on diatoms. This activity lasted as long as 11 hours at higher shoreline elevations or 7 hours at elevations nearer to the lower limits of its distribution. At other times, adults and larger larvae singly occupied individual deeper burrows, whereas some females occupied maternal burrows together with their eggs and small larvae in side galleries; such burrows retained air during immersion by the tide. Griffiths and Griffiths' (1983) account is accompanied by drawings of egg, larva, pupa, and adult.
Teropalpus contains nine species, all with seashore distribution (Newton et al. 2001). Just one (T. lithocharinus) is native to the northern hemisphere, the remaining eight to the southern hemisphere, but one of the latter (T. unicolor), native to New Zealand, Australia, and South Africa, is adventive in Britain and arrived there before 1900. Specimens are found on seashores under driftwood and algae (Makranczy 2006).
Thinobius includes nearly 100 species worldwide (Newton et al. 2001). Most appear to live on banks of streams and ponds and other freshwater habitats, but a few live on intertidal mudflats. Among the latter, are T. frizzelli on the Pacific coast of North America, T. marinus in Singapore, and T. kuroshio on Honshu, the largest island of Japan. Dense populations of T. frizzelli were reported from felted growth of an alga [Lyngyba semiplana (C. Agardh) J. Agardh (Oscillatoriaceae)] in the intertidal zone of Willapa Bay in southwestern Washington State, where the individuals retreated into burrows among the algae when the tide was high; adults are winged, but the wings are of reduced size; adults are thought to eat "detritus"; larvae received a cursory description from Kincaid (1961a). In contrast, T. kuroshio adults were found in decaying drifted seaweed on a pebbly beach (Sawada 1971c), and T. marinus adults were found at Changi, Singapore, on sandy beaches under seaweed (Cameron 1917d). The synonymy of Yosiityphlus with Thinobius was documented by Gusarov and Makranczy (2004).

SCYDMAENINAE CEPHENNIINI
Worldwide, over 4600 species in some 82 genera of this subfamily have been recorded (O'Keefe 2005). Cephennodes araiorum was found under stones on a stony/ sandy beach on the Pacific coast of Honshu, central Japan. It is the only member of the genus known from seashores, the others having been found in leaf litter and rotten deciduous wood at inland sites (Jałoszyński 2003).

PAEDERINAE
About 221 genera of Paederinae occur worldwide; the tribal classification is under revision by L.H. Herman, so subsequent classification may be changed, and the placement of coastal species in the tribe Paederini (below) is uncertain (Thayer 2005).

PAEDERINI
About 200 genera of Paederini occur worldwide. The monotypic genus Chetocephalus is based on C. maritimus, which was found in seaweed on Mauritius (Cameron 1944a).
Medon contains about 350 species worldwide, few of them occurring on seashores. Two exceptions are M. marinus, which was found in seaweed on Mauritius, and M. pocoferus found on the shores of the Mediterranean Sea and the North Atlantic Ocean. Two others are M. prolixus and M. rubeculus, both initially described from Japan, the former first reported from seaweed at Iwosima and Amakusa (Sharp 1874), but the latter was subsequently detected in Hong Kong where it appears to be restricted to the seashore (Rougemont 2001).
Sunius has about 125 species worldwide, but few of these are typically found on seashores. These exceptions are S. ferrugineus from the Caribbean Sea and Sunius minutus from Florida. Both live in drifted seaweed, and they may represent only a single species.
Ophioomma, a genus only recently transferred to Paederini, has only one species, O. rufa. Specimens were initially collected on the Gulf of Mexico coast of Florida, by sifting debris on the beach of Charlotte Harbor.
PHILONTHINA are a subtribe with five genera (Thinocafius, Cafius, Phucobius, Remus, and Orthidus) that appear to be restricted to seashores. Additionally one species each of Bisnius, Gabronthus and Philonthus are also confined to coastal habitats. The systematic position of Thinocafius is unclear and requires study in relation to the phylogeny of Cafius.
Bisnius is moderately large genus with global distribution. Only one species (B. macies) appears to typically be found in drifted seaweed. It was originally described from Japan and was recently detected in Korea (Cho 2008).
Cafius, in its early sense included also species now assigned to Remus. An attempt by Koch (1936) to divide it into subgenera was not completed for all species known at that time, and perhaps for that reason was not followed by some later authors. Later, Coiffait (1963Coiffait ( , 1974 elevated one subgenus (Remus) to generic rank and proposed a new subgeneric name (Suborthidus) to include one species within the remaining species of Cafius. Coiffait's effort to subdivide Cafius applied only to European, North African and Middle Eastern species, and was similarly not followed by some later authors. A global revision of the genus is necessary. In the present study 44 species are listed within Cafius (sensu stricto), making this the most species-rich genus of coastal staphylinids. One seemingly unusual species (C. splendoris Last 1987) is reported from Mt. Amigwiwa 1000-2300 m in Papua New Guinea and is excluded from our list. It may be misassigned to genus. Four species are attributed to Remus (see below). The zoogeographic distribution of species is as follows: Pacific Ocean 29, Atlantic Ocean 8, Indian Ocean 5, Pacific plus Atlantic 1, Pacific plus Indian 1.
The larva of the European C. xantholoma was described by Paulian (1941). Larvae and pupae of the Pacific species, C. canescens, C. lithocharinus, C. luteipennis, and C. seminitens, were described by James et al. (1971). Subsequently Moore (1975) described the larva of C. sulcicollis, although Orth and Moore (1980) stated that it was actually the larva of C. bistriatus. More recently, Ahn (2002, 2007) used DNA sequence data to associate field-collected larvae with identified adults, and were able thus to identify and describe larvae of C. histrio, C. mimulus, C. rufescens, C. fucicola, C. nauticus, and C. vestitus from the Pacific. The European C. xantholoma is the best investigated species. Backlund (1945) compared the attractiveness of sterile leaves of various flowering plants versus sterile Fucus fronds and found that 26 adult specimens chose Fucus versus only four that chose other leaves. Cafius xantholoma is predacious as adult and larva, and is stenotopic in deep layers of seaweed beds (Backlund 1945). Observations of C. xantholoma larvae throughout the year (Backlund 1945;Egglishaw 1965) suggest that the species is multivoltine. Adults of C. xantholoma are highly resistant to wetting and may take flight directly from the water surface (Backlund 1944), and adults of C. bistriatus show the same ability to avoid wetting and drowning (Frank et al. 1986). On the Pacific coast, mass flights of beetles including C. luteipennis have been observed and generally are in a direction parallel to the shore (Leech and Moore 1971;Evans 1980). We are unaware of reports of brachyptery among Cafius species. The distribution of Cafius species along the coast of the United States from New Jersey south to Florida and the Gulf of Mexico is determined by the abundance of drifted algae (not drifted seagrasses or marshgrasses), and some algae, for example Sargassum fluitans Borgessen, appears not to provide suitable habitat (Frank et al. 1986). The wider distribution of species originally described from the West Indies is still not determined although Frank (1985a) reported C. caribeanus from the South American mainland, and C. subtilis from Florida (USA). There are also questions about the relationship between C. subtilis and C. aguayoi (described from Massachusetts, USA), and of these to the European species now known as Remus sericeus. A report of C. xantholoma from Chile was later shown to be based on misidentification. Most species of Cafius are found on the Pacific Ocean shores, and only one species (C. bistriatus) occurs both there and on the Atlantic. It is believed to have colonized Atlantic coasts from the Pacific, and the two populations have been distinguished morphologically at the subspecific level (Frank et al. 1986). On a sandy beach in Somalia, adults of three Cafius species (C. fonticola, C. nauticus, and C. raggazzii), were trapped more abundantly in the dry season than in the wet, and were more active at night in the dry season than in the wet (Chelazzi et al. 1983).
Gabronthus was recognized as a genus distinct from Philonthus in 1955. It contains over 30 species; only one of these, G. maritimus, found in the Mediterranean, the Red Sea, the Indian Ocean, and the South China Sea, appears to be restricted to coastlines. A report of G. maritimus from Cuba is highly questionable and without voucher specimens so has not been accepted in this study.
Orthidus contains only one species (O. cribratus) found on the Mediterranean coasts of southern Europe and northern Africa, and Atlantic coasts from Brittany (France) south to Morocco. It dwells under rocks and in piles of drifted algae on seashores (Coiffait 1974).
Philonthus nudus was for many years misattributed to Cafius, perhaps because of its atypical (for the genus Philonthus) coastal habitat. Its populations are distributed on the coasts of Korea, Japan, and the Kuril Islands of Russia, to the Pacific coasts of Canada and the United States, typically in drifted seaweed. Philonthus is a genus of over 1,000 species.
Phucobius contains eight species, of which seven are found under seaweed on beaches. The eighth (P. africanus) was reported from a single specimen collected at 1600 m in western Usambara, Tanzania. The collection locality has been confused, or perhaps the species belongs to another genus. Six species inhabit shorelines of the western Pacific (including the East Sea, South China Sea, and Java Sea, but not farther north than Japan), and one is found the shores of the Indian Ocean. Sharp (1874) recorded P. simulator as common under seaweed at Amakusa and Iwosima, Japan.
Remus contains four species, all found in drifted seaweed on coastlines. One species (R. sericeus) occurs on coasts of the North Atlantic, Baltic, Irish, North, Mediterranean, and Black seas and, remarkably, in Australia. Another species (R. filum) is confined to the coasts of the Mediterranean and Black seas. Another species (R. pruinosus) is known from coasts of the North Atlantic, North, and Mediterranean seas. Another species (R. corallicola) is known from the South Pacific, South China, and Java seas, the Indian Ocean, and the Red Sea. The larva and pupa of R. sericeus were described and illustrated by Paulian (1941). Bierig (1934a) did not record R. pruinosus from Cuba as listed by Peck (2005). On a sandy beach in Somalia, adults of two Remus species (R. corallicola and R. filum), were trapped more abundantly in the dry season than in the wet (Chelazzi et al. 1983).
Thinocafius contains only one known species, T. insularis, which is known only from the Chatham Islands east of New Zealand.
QUEDIINA are a subtribe containing one genus (Quediocafus) that appears to be restricted to seashores. One or more members of two other genera (Heterothops and Quedius) may or may not be restricted to seashores.
Heterothops is a widespread genus. Only one species, the North American H. asperatus, appears to be confined to Pacific seashores. The European H. binotatus (Gravenhorst) is often but not exclusively found on seashores and so is not included.
Quediocafus is known only from New Zealand, and all three species appear confined to sea beaches. Marris (2000) mentioned that Q. insolitus was found "under tussock mats and among coastal vegetation".
Quedius is a large and widespread genus apparently without any coastal specialists. Quedius simplicifrons Fairmaire (1861), which has several synonyms and is widely distributed at and near the coasts of western Europe and adjacent islands, does not meet our definition of a strictly coastal species. Quedius umbrinus Erichson (1839a), which Mjöberg (1906) found to be the most abundant insect in drifted seaweed at Bohuslän in southwestern Sweden, is not included because it also occurs in inland habitats.
STAPHYLININA are a subtribe containing the strictly coastal genera Thinopinus, Hadrotes, Hadropinus, and Liusus, as well as genera that are not confined to seashores.
Thinopinus pictus, occupying sandy Pacific beaches of North America from Alaska south to Baja California, has adults that are mottled dark and pale ('melanic') on dark sand beaches, but pale on pale sand beaches (Malkin 1958). Malkin (1958) pointed out that adults are nocturnal, spending the day concealed, and was perplexed as to why there should be two color forms. On beaches near Goleta (California, USA), adults and larvae are present throughout the year; dissected females contained 2-3 eggs, which are laid singly beneath the sand and hatch in ~ 14 days (Craig 1970). These eggs are white and ~ 3.0 mm long and 2.2 mm wide. Larval development time was not determined, but larvae were observed at night running on the sand surface like the adults (Craig 1970). On the western shore of Vancouver Island (British Columbia, Canada), the main prey is Orchestia californiana (Brandt), an amphipod which spends the day in temporary burrows on the upper part of the beach and is ambushed at night by the adult beetles (Richards 1982). The activity pattern of the amphipod is adjusted to weather and tidal patterns, and on some nights it is active after midnight, whereas beetles are active soon after dark; thus, beetles often foraged when amphipods were inactive (Richards 1983). Beetles attacked 0.147 amphipods per minute and captured 9.1% of prey attacked (Richards 1984). Color photographs of a larva (15 mm long) and adults of the two color forms (16-18 mm long) were provided by Evans (1980).
Hadrotes crassus lives on the Pacific coasts of North America, and is found from Alaska south to Baja California. Its larva was described by Moore (1964b) and color photographs of adult (11-17 mm) and larva (14-16 mm) are provided by Evans (1980); adults and larva are nocturnal predators of crustaceans and insects. A species described from New Zealand as Hadrotes wakefieldi may belong to another, possibly undescribed, genus (Klimaszewski et al. 1996).
Hadropinus fossor is an old-world representative of the subtribe, inhabiting the shores of northern Japan and of Sakhalin Island (Russia). It makes burrows in sand under seaweed (Sharp 1889).

Discussion
Many kinds of insects can be found, some of them dead or dying in sea drift on shorelines. Many are winged insects that have alighted on the sea surface and have subsequently been washed up on the shore. Non-coastal species may exploit such concentrations of food. The senior author observed a pile of lawn grass clippings on a beach in Guanacaste, Costa Rica, that produced an abundance of staphylinids, none of them coastal species. Thus, would-be collectors of coastal staphylinids may be misled by the mere presence of staphylinids on seashores -a knowledge of non-coastal genera is essential. Coastal species represent only about 0.7% all Staphylinidae, although almost 400 species of them are known. Some representative species are shown in Figures 6-8.
Aleocharinae are the most species rich of the eight subfamilies with coastal representatives (Fig. 9). The Pacific Ocean has many more species of coastal staphylinids than do the other oceans (Fig. 10). The United States has more species of coastal staphylinids than do eight other countries (Fig 11). Lawrence and Newton (2000) and Newton et al. (2001) recognized four lineages among the Staphylinidae, and included among them the Pselaphinae and Scydmaeninae (Fig. 1). All four lineages contain genera and species that are restricted to coastal habitats. Coastal genera and species are found in eight subfamilies which contain mainly non-coastal genera. No subfamily contains only coastal genera. It is not until the level of tribe that there are taxa-all of them in the Aleocharinae-that include exclusively coastal genera.

Polyphyly of coastal Staphylinidae
The evolution of coastal genera in the Staphylinidae is polyphyletic. They have arisen from non-coastal ancestors among eight subfamilies. Furthermore, many coastal species belong to genera that include non-coastal species. Thus, we should expect a diversity of structural, physiological, and behavioral adaptations among them.

The Pacific ocean as the main evolutionary center
Selecting only those genera that are exclusively coastal and separating them into three groups according to their provenance, yields the following: Coastal genera from the Pacific only: 40 From the Pacific and elsewhere: 14 From anywhere except the Pacific: 10 The Pacific Ocean (including its various seas such as the East Sea and South China Sea) is clearly the major cradle of coastal Staphylinidae.  Coastal staphylinids have arisen within all four major lineages of the family, and even within these lineages they are polyphyletic. The simplest explanation is that the Pacific is oldest ocean (having arisen from the ancient ocean called Panthalassa). An alternative explanation might be that the shores of the Pacific are longer than the shores of other oceans, and somehow the species/area relationship (which has generally been supported for the staphylinid fauna of land masses) would suggest greater diversity on Pacific shores. A second alternative might be that non-coastal staphylinid faunas in lands surrounding the Pacific are more diverse than elsewhere and somehow had greater genetic plasticity. A third alternative might be that somehow the Pacific coasts have or had a special abundance of suitable habitat.
The ten genera not represented in the Pacific are: European (Actocharis, Brundinia, Pseudopasilia, and Phytosus), far South Atlantic (Chilodera and Acticola), Caribbean (Briaraxis), Gulf of Mexico (Ophioomma), and South Atlantic and Indian Ocean (Pareiobledius and Chetocephalus). Briaraxis, Chilodera, Acticola and Ophioomma are monotypic and because there are few specimens with habitat information, it is not certain whether the latter three are truly coastal. Europe, with four genera in the North Atlantic Ocean (and/or Mediterranean, Black, North, Irish, and Baltic seas) falls second to the Pacific Ocean in terms of precinctive genera.
Actocharis and Phytosus are currently placed in the tribe Phytosini. This tribe includes two other genera that have representative species in the Pacific. Unfortunately, this tribe requires revision and its monophyly is uncertain. Therefore, it is not clear whether Actocharis and Phytosus evolved from coastal ancestors that immigrated from the Pacific, or whether they evolved from non-coastal European ancestors. The discovery of a species of Phytosus in the Caribbean is discussed later. Apart from whether Chilodera and Acticola are truly coastal, their attribution to the South Atlantic Ocean needs qualification because they are known only from the Falkland Islands. Could they have a yet undetected distribution elsewhere? Another coastal genus, Crymus, has two species, distributed in the South Atlantic Ocean (Falkland Islands and South Georgia) and South Pacific Ocean (the Campbell and Auckland Islands of New Zealand) thus having a sub-Antarctic distribution. None of these genera extends farther north. Antarctic seas do not seem to have provided a conduit for migration of less cold-hardy coastal staphylinids around Cape Horn or the Cape of Good Hope. Forty genera remain confined to the Pacific and have not been detected in the South Atlantic. Among the 14 genera that are known from the Pacific and elsewhere, only two (Halobrecta and Diglotta) have species in the South Atlantic: H. algophila, which may have arrived adventively via shipping activities, and D. brasiliensis.
Even the Arctic Ocean has a partially coastal species (Micralymma brevilingue) whose congener, M. marina, is truly coastal and extends south through the Atlantic Ocean, east to the North and Baltic seas, and west to New England and Atlantic Canada. A third species (M. laticolle), also from the Arctic Ocean, does not belong to Micralymma (see Habits, Habitats, and Classificatory Notes), and should be transferred to another genus. A fourth species, in Eurasia, is not coastal.
The foregoing discussion suggests that almost all coastal genera of Staphylinidae evolved from non-coastal ancestors on the shores of the Pacific Ocean. Some apparently dispersed by migrating to the shores of other oceans. Geological constraints are outlined below.
The primordial ocean surrounding Pangaea in the Permian was Panthalassa, generally accepted as the direct antecedent of the Pacific Ocean (Scotese 2010). The breakup  of Pangaea into Laurasia and Gondwanaland began by formation of the Tethys Sea which was the antecedent of the Indian Ocean and the Red Sea. Earlier authors (1960s) included the Mediterranean Sea, but recent authors credit the Mediterranean as being a separate entity, perhaps part of the Neotethys ocean basin, formed ca. 200 mya. The separation of Laurasia continued during the Triassic with the beginning of the North Atlantic Ocean. In the Jurassic, the North Atlantic Ocean widened and the Tethys Sea began to narrow. Not until the Cretaceous did the South Atlantic Ocean began to widen. In the Eocene, the South Atlantic Ocean became connected to the South Pacific Ocean by opening of the Drake Passage between Antarctica and South America some 41 mya (Scher and Martin 2006). The Mediterranean Sea lost its connection to the Indian Ocean some 15 mya. About 7 mya, the Mediterranean lost its narrow connections to the North Atlantic, its waters evaporated and it became a salt desert. At 4.86-4.6 mya, the Strait of Gibraltar opened, and water poured in from the North Atlantic in an immense flood (Garcia-Castellanos et al. 2009). The North Atlantic Ocean lost a major connection to the Pacific Ocean by completion of the Central American isthmus 3.5-3.1 mya (Bartoli et al. 2005). This is the geological background against which the current distribution of coastal Staphylinidae may be understood. It suggests that the Tethys Sea (and its extension, the Neotethys ocean basin), could have offered an early conduit from the Pacific via the Mediterranean to the Atlantic until the connection between the Mediterranean and Indian Ocean was lost, some 15 mya. However, between 7 and 4.8 mya, the Mediterranean became a salt desert and surely lost those parts of its coastal fauna that could not tolerate extreme salinity and aridity; the coastal Staphylinidae that had dispersed to the Atlantic could have survived, but other populations would have become extinct within the Mediterranean. [This ac- The width of the north Pacific ocean has not been a severe barrier Liparocephalini (Aleocharinae) include seven genera containing 24 species, and all species are coastal. Five genera inhabit the North Pacific Ocean only, and four of them have representatives on both sides of it (i.e., in Asia and in North America). However, only two of the 24 species, Diaulota aokii and Paramblopusa borealis, occur on the shores of both continents. This suggests that the width of the North Pacific Ocean has not been a severe barrier to dispersal, and that most dispersal occurred in the remote past, allowing subsequent speciation. Ahn et al. (2010) showed that the distribution of Liparocephalini was congruent with geological history, including the splitting of Pangaea and the isolation of the Palearctic from the Nearctic. They hypothesized that the ancestor of the tribe was distributed along the Panthalassan Ocean and repeated dispersals occurred into the Nearctic from the Palearctic.
Although these insects, presumably with favorable currents and winds, may cross oceans, we must suspect that barriers are formed by intervening land masses. This suspicion is heightened by dearth of records from inland localities, with just a few from California's Salton Sea (which once was connected to the Gulf of California). Thus, the biogeography of coastal staphylinids differs greatly from that of non-coastal species.

Westward dispersal across the Atlantic to the Caribbean
Phytosus (Aleocharinae: Phytosini) has five European species, the range of two of which includes the Canary Islands; their presence on these islands suggests an ability to disperse. Three other species are known: one from the Azores, one from Senegal, and one from Guadeloupe in the Caribbean. Their ancestors are postulated here to have dispersed from Europe in the remote past. The westward dispersal of the putative ancestor of P. caribeanus across the Atlantic at the latitude of the Caribbean could have been assisted by trade winds.
Heterota (Aleocharinae: Homalotini) contains three species in the Pacific, three in the Indian Ocean, two in the Red Sea, and one in the Mediterranean. A tenth species (H. plumbea) inhabits the Atlantic coasts of Europe, the Mediterranean, and the Canary Islands. It has also been found in the Caribbean (Jamaica and the Yucatan peninsula of Mexico) and Florida (Frank and Thomas 1984b). Small winged insects adapted to a seashore existence could be prime candidates for transoceanic dispersal by the prevailing winds such as from southern Europe or northern Africa to the Canary Islands and thence to the Caribbean.

Northward dispersal from the Red sea to the Mediterranean
The Red Sea may have been a conduit for dispersal from the Indian Ocean to the Mediterranean. If such dispersal did occur, a subsidiary question is whether it occurred recently, after the building of the Suez Canal, whether it occurred long before that and east or west of the Sinai Peninsula, or whether it occurred in the remote past before sea connections between the Red and Mediterranean seas closed ~15 mya. In this context it is worth noting that there is no evidence for dispersal of coastal staphylinids from the Indian Ocean via the South Atlantic to the North Atlantic.
Heterota (Aleocharinae: Homalotini) has three species in the Pacific, three in the Indian Ocean, two in the Red Sea, and one in the Mediterranean (and one, previously mentioned, distributed from the Mediterranean to the Caribbean). Current distribution suggests that the Red Sea may have been an ancient conduit to the Mediterranean.
Cameronium (Aleocharinae: Homalotini) contains three species in the Indian Ocean, one in the Red Sea, and one (C. liebmanni, not listed) at inland localities in Algeria, adjacent to the Mediterranean. Current distribution suggests that the Red Sea may have been an ancient conduit to the Mediterranean. Could C. liebmanni have found refuge at inland locations as the Mediterranean Sea became a salt desert ca. 7 mya? A species from the Gulf of California was attributed to this genus by Moore (1964a), but this assignment needs reassessment.

Eastward dispersal from the Pacific to the Atlantic
Cafius subgenus Euremus contains 10 species in the Pacific and a few others elsewhere. Because C. bistriatus has one subspecies (C. b. bistriatus) on the Caribbean and Atlantic coasts of North America, and one subspecies (C. b. fulgens) in the Gulf of California and on the Pacific shores of California and Baja California, it has been posited that it and the ancestor of C. rufifrons arrived in the Caribbean from the Pacific (Frank et al. 1986). If Central America is now an insuperable barrier to such dispersal, then the date of dispersal was probably before the connection of Central America to South America 3.5-3.1 mya.
Aleochara litoralis (Aleocharinae: Aleocharini) occurs on the Atlantic coast of North America from Florida north to Newfoundland and Quebec, as well as on the Pacific coast from California north to Alaska. There has been no report of specimens from the Canadian Arctic that could explain a natural dispersal.

The distribution of coastal species of non-coastal genera
Selecting the coastal species belonging to non-coastal genera and placing them into the same categories as in preceding list yields the following: Coastal species of non-coastal genera from the Pacific only: 10 genera, 39 species From the Pacific and elsewhere: 3 genera, 4 species From anywhere except the Pacific: 13 genera, 35 species The genus Bledius is excluded from this compendium.
Here, it can be seen that the numbers of genera and species from the Pacific only are almost identical to those from anywhere except the Pacific. The species included are such as Philonthus nudus and Heterothops asperatus (Pacific Ocean), Medon pocoferus (Mediterranean), M. marinus (Indian Ocean), M. prolixus (Japan), Sunius ferrugineus (Caribbean), and S. minutus (United States). They belong to genera that have many non-coastal species. Although they have evolved to occupy coastal habitats, their anatomical characters do not set them apart as belonging to genera that are distinct from the non-coastal ancestors. In other words, their adaptation to coastal habitats is probably more recent than in genera that consist only of coastal species.

The genus Bledius is a special case
We do not include the genus Bledius in the above accounts because we believe it is a special case, with possibilities of overland dispersal during its evolution.

Effects caused by humans
There can be few species that have not been affected by human activity, and coastal staphylinids are no exception. Teropalpus unicolor is native to New Zealand and now occurs adventively in Australia, South Africa, on the Pacific coast of North America, and the south and southwest coasts of Britain (Hammond 2000). Adota maritima (syn. Atheta immigrans) is known from the Pacific coast of North America and adventively from Britain (Easton 1971, Hammond 2000. The European Halobrecta flavipes is another likely candidate for a list of species dispersed by shipping because it has been detected on the coasts of Chile, Australia, and eastern Canada. Another European species recently detected on the Atlantic coast of Canada is Diglotta mersa . The building of seawalls for construction of marinas and docks, and for protection of buildings from wave action, damages beaches and in some places may harm coastal staphylinid populations. The senior author remembers that drifted seaweed accumulated on a beach by the west end of a bridge at Ft. Pierce, Florida in the early 1970s and harbored Cafius species. Twenty years later, the area had become a marina with seawalls and without seaweed accumulations; very many undocumented changes are likely to have been caused by similar constructions elsewhere. Human enjoyment of beaches to some extent depends upon the cleanliness of the beaches, and humans have employed beach-sweeping machines to remove not only garbage but also 'un-sightly' drifted marine algae, which are the habitat and basis for food chains for some coastal staphylinids (Frank et al. 1986). An unusual sign at a public beach at Santa Barbara, California in summer 2009 (seen by the senior author) explained that seaweed was not being cleared there because it was the habitat of invertebrate animals that serve as food for birds. Oil spills on beaches are surely harmful to staphylinid populations, although we have seen no documentation. The compaction of beaches by human activity (vehicular as well as crowds of people) may be detrimental to Staphylinidae. Recently much-discussed threats to coasts and oceans are a rise in sea level and acidification, but their potential effect on coastal staphylinid populations have not been discussed in print if at all.

Summary
1. Not all Staphylinidae found on seashores are coastal. 2. Coastal Staphylinidae comprise <1% of all species of Staphylinidae. 3. Coastal Staphylinidae have arisen in eight of the subfamilies, are polyphyletic, and have diverse adaptations of structure, physiology, and behavior that allow them to exist in such habitats. 4. There are far more strictly coastal genera in the Pacific than elsewhere and the Pacific appears to be the most important evolutionary center for this group. 5. There are approximately as many coastal species (belonging to otherwise noncoastal genera) in the rest of the world as there are in the Pacific.

Acknowledgments
When JHF began a literature search, he already had originals or copies of most of the cited publications in his personal library. In early summer 2001, he began to request interlibrary loans through the University of Florida libraries (thanks especially to Janice Kaehler) for items he did not have and were not held by the University of Florida libraries. He thanks several friends for providing copies of pages of articles and books that the Interlibrary Loan Service of the University of Florida was unable to provide: