The integripennis species group of Geocharidius Jeannel, 1963 (Carabidae, Bembidiini, Anillina) from Nuclear Central America: a taxonomic review with notes about biogeography and speciation

Abstract Our review recognizes 15 species of the integripennis species group of Geocharidius from Nuclear Central America, include three species previously described (Geocharidius gimlii Erwin, Geocharidius integripennis (Bates) and Geocharidius zullinii Vigna Taglianti) and 12 described here as new. They are: Geocharidius andersoni sp. n. (type locality: Chiapas, Chiapas Highlands, Cerro Huitepec) and Geocharidius vignatagliantii sp. n. (type locality: Chiapas, Motozintla, Sierra Madre de Chiapas, Benito Juárez) from Mexico; Geocharidius antigua sp. n. (type locality: Sacatepéquez, 5 km SE of Antigua), Geocharidius balini sp. n. (type locality: Suchitepéquez, 4 km S of Volcan Atitlán), Geocharidius erwini sp. n. (type locality: Quiché Department, 7 km NE of Los Encuentros), Geocharidius jalapensis sp. n. (type locality: Jalapa Department, 4 km E of Mataquescuintla), Geocharidius longinoi, sp. n. (type locality: El Progreso Department, Cerro Pinalón), and Geocharidius minimus sp. n. (type locality: Sacatepéquez Department, 5 km SE of Antigua) from Guatemala; and Geocharidius celaquensis sp. n. (type locality: Lempira Department, Celaque National Park), Geocharidius comayaguanus sp. n. (type locality: Comayagua Department, 18 km ENE of Comayagua), Geocharidius disjunctus sp. n. (type locality: Francisco Morazán, La Tigra National Park), and Geocharidius lencanus sp. n. (type locality: Lempira Department, Celaque National Park) from Honduras. For all members of the group, adult structural characters, including male and female genitalia, are described, and a taxonomic key for all members of the integripennis species group is presented based on these characters. Behavioral and biogeographical aspects of speciation in the group are discussed, based on the morphological analysis. In all cases of sympatry, pairs of closely related species show greater differences in sizes than pairs of more remotely related species. Integripennis group species occupy six different montane areas at elevations above 1300m, with no species shared among them. Major faunal barriers in the region limiting present species distributions include the Motagua Fault Zone and a gap between the Guatemalan Cordillera volcanic chain and the Honduran Interior Highlands no higher than 900m in elevation. Highest species diversity is in the Guatematan Cordillera (six species), second highest in the Honduran Interior Highlands area (four species).


Introduction
Geocharidius Jeannel, 1963 was established for a Guatemalan species, G. integripennis (Bates), described in "Biologia Centralia-Americana" (Bates 1882). Jeannel's description of Geocharidius omitted or misinterpreted several important morphological details, leading Vigna Taglianti (1973) to re-describe the genus on the basis of the two species, G. integripennis and G. zullinii Vigna Taglianti, known to him at that time.
Providing new evidence, Vigna Taglianti (l.c.) proposed a new phyletic lineage for Geocharidius, which had been placed by Jeannel (1963) in a lineage with the Mediterranean Geocharis Ehlers and Rhegmatobius Jeannel. The new lineage integrated the New World anillines of Jeannel's "scotodipnienne" stock of genera (i.e. those taxa, members of which have a mental tooth along with the umbilicate series of elytral pores of type B (Jeannel 1937), where pores 7 and 8 and 8 and 9 are separated from each other by equal distances. According to Vigna Taglianti (1973) this lineage included also Mexanillus Vigna Taglianti, described in the same paper, and perhaps also Mystroceridius Reichardt (1970) from the Galapagos Islands. Since then, several new genera of the "scotodipnienne" stock of anilline genera have been described from the New World (Zaballos 1997;Mateu and Etonti 2002). At present, Geocharidius includes 5 species (Lorenz 2005;Zaballos 2004), four of which are limited in their distribution to Guatemala (Erwin 1982). Ecologically, representatives of Geocharidius are adapted for life in forest litter, and these beetles are comparatively easy to collect using litter sifting techniques.
From 2008 to 2011, the "Leaf Litter Arthropods of Mesoamerica" (LLAMA) project (http://llama.evergreen.edu/) generated the first significant samples of the leaf litter invertebrate fauna of Mesoamerica (including southern Mexico). This project focused on sampling ants and weevils from the litter layer of the tropical forest floor, but it also sampled many different non-target taxa, including many litter anillines. By 2012, the second author (DHK) had assembled on loan most available material representing Mesoamerican Anillina at the California Academy of Sciences, San Francisco. Several hundred specimens of the subtribe were borrowed from the collections of the six institutions noted below. This material served as the basis of and inspiration for the current report. In this paper, we present the results of a taxonomic study of one intrageneric group of species of Geocharidius, the integripennis species group.

Materials and methods
This study is based on examination of 455 specimens belonging to the integripennis group of species of Geocharidius, which includes 15 species. Material was borrowed from and/or is deposited in the following institutions, identified in the text by the following associated codens: Verbatim label data are given for type specimens of all newly described taxa, with label breaks indicated by a slash ("\"). For a series of KUNHM specimens with the same geographical labels but differing in various barcode numbers only, these numbers were replaced in the text by periods of ellipsis ("…").
Measurements. All specimens were measured electronically using a Leica M420 macroscope equipped with a Syncroscopy AutoMontage photomicroscopy system (SYNCROSCOPY, Synoptics Ltd.). Measurements for various body parts are encoded as follows: LH = length of head, measured along midline from anterior margin of labrum to a virtual line connecting posterior supraorbital setae; WH = width of head, at level of anterior supraorbital setae; WPm = maximum width across pronotum; WPa = width across anterior angles of pronotum; WPp = width across posterior angles of pronotum; LP = length of pronotum from base to apex along midline; WE = width of elytra, at level of 4 th umbilicate setae; LE = length of the elytra, from apex of scutellum to apex of left elytron; SBL = standardized body length, a sum of LH, LP and LE. Measurements of SBL are given in millimeters; others are presented as eight ratios: mean widths-WH/WPm and WPm/WE and body parts-WPa/WPp, WPm/WPp, WPm/LP, WE/LE, LE/SBL and WE/SBL. All values are given as mean ± standard deviation.
Illustrations. Digital photographs of the dorsal habitus of new species were taken with the AutoMontage system using a Leica M420 macroscope. Line drawings of selected body parts were made using grids on a Labomed Lx400 compound microscope. Scanning electron micrographs were made with coating on a LEO 1450VP SEM. Diagrams were prepared using Statistica 6.0. (StatSoft Inc.).
Dissections. Dissections were made using standard techniques. Genitalia were dissected from abdomens of specimens previously softened in boiling water for 20-30 minutes. Contents of the abdomen were cleared using boiling 10% KOH for 2-3 minutes to remove internal tissues, and then washed in hot water before examination. After examination, genitalia were mounted on plastic transparent boards in dimethylhydantoin formaldehyde resin (DMHF) and pinned beneath the specimen. In some species, investigation of body parts was undertaken in the following way. The whole specimen was cleared using boiling 10% KOH for ~5 minutes, then washed and dissected. Disassembled body parts from a single specimen were placed on plastic transparent cardboard, properly oriented, mounted in DMHF and pinned together with the specimen labels.
Type material. The authors had no opportunity to investigate type material of the Mexican species of Anillina described by A. Vigna Taglianti. The identification of Geocharidius zullinii was made only on the basis of the original description of the species (Vigna Taglianti 1973). Types of the Guatemalan species of Geocharidius described by T. L. Erwin in his revision of Central American Bembidiini (Erwin 1982) were examined. All paratypes listed in the treatments for new species have been labeled with appropriate yellow paratypes labels, which have not been included in the verbatim label data provided for each specimen.
Terms. Terms used in the paper are largely of general use and follow the literature (Ball and Bousquet 2000;Shpeley 2005, 2009;Erwin 1974;Jeannel 1963), except those for ventral surface structures, terms for which follow the Handbook of Zoology (Lawrence et al. 2010). We use the term "dorsal sclerites" (eg. Fig. 9A, D, E and H) to refer to a complex of more or less sclerotized plates and/or flagellum-like pieces in the dorsobasal region of the retracted internal sac of the male median lobe. These sclerotized elements are highly varied in their size, shape and number and/or degree of fusion among males of different species of this species group, and we have not yet distinguished individual homologies among the varied elements. However, we distinguish this complex of sclerites as a group from the "ventral sclerites" complex found in males of many species of Anillinus Casey (1918) along with the dorsal sclerite complex (eg., see Sokolov 2014, fig. 6K, vsc). We defined Nuclear Central America as the region between the Isthmus of Tehuantepec and the Nicaraguan Depression (Schuchert, 1935).
Species ranking. Species recognition is in accordance with our previous approach (Sokolov et al. 2004), except for cases explained in the text.
Arrangement of taxa in the text. Taxonomic treatments of species are arranged separately by country for the region (i.e. Mexico, Guatemala and Honduras) consistent with the geographical distinctions made in our key to species. For each country, species treatments are arranged in alphabetical order..
Descriptions. The scheme of description generally follows that of Shpeley (2005, 2009).
Map. The map (Fig. 22) was downloaded from the web-site: http://www.mapsfor-free.com/ and adjusted using Adobe Photoshop® software.

Geocharidius Jeannel
Geocharidius Jeannel, 1963: 107 (type species Anillus integripennis Bates, 1882, by original designation) Recognition. The members of this genus are distinguished from those of the other North and Central American Anillina by the following combination of characters: frontal area of head with small median tubercle; maxillary palps with palpomere 4 shorter than 1/4 that of palpomere 3; labial ligula without paraglossae, mentum and submentum separated by mental-submental suture; pronotum convex, with short vestiture throughout, including the areas forward of the lateral setae; elytra without fixed discal setae and with the 7 th and the 8 th and the 8 th and the 9 th pores of the umbilicate series separated by equal distances; metendoventrite linear without lateral arms; and intercoxal process between the hind legs widely triangular (Sokolov 2013). Included taxa. The species of Geocharidius, as treated at present (Lorenz 2005), are arranged in two groups, based on body form: those with a subdepressed form and those with a globose habitus (Erwin 1982). Species with members subdepressed in habitus  correspond to the type species of the genus and are treated below as the integripennis species group. Members of the genus with a globose habitus (Fig. 2D), like Geocharidius phineus Erwin, Geocharidius romeoi Erwin and similar undescribed species, are not treated in this report.

The integripennis species group
Recognition. Members of this group are distinguished from the other representatives of the genus by the following combination of external characters: head totally covered with microlines, microsculpture mesh pattern isodiametric (Figs 1A-C) and elytra only moderately convex (subdepressed) . Most species also have members with the elytra totally covered with microlines in form of isodiametric mesh pattern (Figs 1G-H), males with long copulatory sclerites of the internal sac (Figs 9,13,19) and females with simple, not bilobate, spermatheca (Figs 11,17,21 Vestiture. Body surface covered with sparse yellow setae of moderate and more or less equal length throughout. Fixed setae. Primary head setae include one pair of clypeal, one pair of frontal and two pairs of supraorbital setae. Mentum (Fig. 5) with two pairs of long primary (paramedial [pms] and lateral [lms]) setae. Submentum (Fig. 5) with three groups of setae: two (Fig. 5D) to three (Fig. 5C) in medial row (mss), two (Fig. 5F) to three (Fig. 5C) Figures 2. SEM illustrations of structural features and shape of elytra of Geocharidius species, left lateral aspect. A G. erwini B G. jalapensis C G. comayaguanus D G. phineus. Legend: ed2 -scutellar seta; ed8 -apical seta; eo1-9 -setae 1-9 from the umbilicate series. Scale = 0.2mm. in lateral rows (lss) and one pair of primary basal setae (prss). Elytra without discal setae (Fig. 2), but with scutellar (ed2) and apical setae (ed8) present. Last three (7 th , 8 th and 9 th ) pores of umbilicate series (eo7, eo8 and eo9) in line and equally spread apart (Fig. 2B). Fifth abdominal ventrite  of male with one pair (Fig. 3H) and of female with two pairs (Fig. 3I) of abdominal setae along the posterior margin.
Head . Anterior margin of clypeus straight. Frontal area with small tubercle medially near frontoclypeal suture. Fronto-lateral carinae distinct and long.
Labrum . Transverse with straight, entire anterior margin, with six setae apically, increasing in size from central pair outward.
Prothorax. Pronotum cordiform, of moderate length (LP/SBL varied from 0.23 to 0.24 among species, LP/LE varied from 0.38 to 0.42 among species), moderately convex, not sinuate posteriorly. Basal margin of pronotum with slightly protruding medial portion. Anterior angles indistinct, broadly rounded. Posterior angles denticulate, with two or three small denticles anterior to angles. Prosternum ps) slightly protruding at the anterior margin medially, there with a group of longer setae relative to other prosternal vestiture, also with a pair of long ambulatory sensor setae (pas) at the middle of sclerite. Prosternal intercoxal process unmargined, slightly dilated apically and obtusely truncate at apex, with a row of sparse setulae along midline.
Scutellum. Externally visible, triangular, with rounded apex. Elytra. Moderate in length (LE/SBL varied from 0.57 to 0.60 among species), without visible interneurs. Basal margination varied (long in some species, extended halfway between humeral angle and scutellar pore bm), very short in others, length about equal to diameter of basal setiferous pore socket (Fig. 1G)) but distinct in all species. Lateral elytral margin without subapical sinuation in apical half.
Male genitalia. Median lobe of aedeagus anopic, elongate, arcuate and twisted. Internal sac with dorsal copulatory sclerites only, which are long, longer than half of length of the median lobe, except in G. comayaguanus male in which they are rather short . Sclerites in form of a long plate, rounded or pointed at basal end, and typically tapered into a long flagellum in apical half, in a few species tapered as a short blade-like structure. Additional spines of internal sac absent. Parameres bisetose. Left paramere large and relatively narrow, mostly with long and narrow apical constriction. Right paramere small and narrow. Ring sclerite (Figs 10,16,20) ovate or triangular-ovate with an elongate handle-like extension of varied shape.
Female internal genitalia. Spermatheca simple (Figs 11,17,21), not bilobate, either unsclerotized fusiform or sclerotized of varied shape, typically fusiform with a bulb-like enlargement apically, straight or bent rectangularly. Parts of spermatheca mostly undifferentiated and named in relation to point of attachment of the spermatecal gland: cornu from point of gland attachment to the apex, and nodulus from point of gland attachment to point of duct attachment (Fig. 11). The ramus, the protruding area of attachment of the spermathecal gland (Maddison 1993), is flat and not developed in the species under consideration here.
Geographical distribution. The species of this group now are known from mountain ranges of southern Mexico (state of Chiapas), Guatemala and Honduras (Fig. 22).
Way of life. According to label information, specimens of this group were collected from leaf litter within the 2050-2950 m elevation range in the mountains of southern Mexico, within the 1600-3200 m range in the mountains of Guatemala, and within the 1300-2500 m range in the mountains of Honduras. Beetles were extracted from litter in oak, pine, pine-oak, mixed hardwood (without oaks), cloud and lower and upper montane forests. Months of collection include May through September and November.
Relationships. The position of the integripennis group species within the genus is unclear at present and awaits further morphological study of the globose representatives of Geocharidius and a molecular phylogenetic analysis of all species.

A key for identification of adults of the integripennis species group of Geocharidius Jeannel
The following key includes all known members of the integripennis species group. The key makes use of distributional information because each of the three countries mentioned has its own Geocharidius assemblage, the ranges of which are non-overlapping with those of neighboring countries. Our current information on species distributions may prove to be incomplete with additional sampling, so dissection and examination of genitalia should be used for confirmation wherever possible.

1
Body form slightly to moderately convex  and EITHER with head ( Fig. 1A-C) and elytra  totally covered with microsculpture throughout OR, if only head covered with microsculpture, then elytra subparallel with prominent rounded humeri (Fig. 8C)   Pronotum with basal margin wider (WPa/WPp<1.03). If pronotum smooth, then proepisternum with microsculpture. If male with dorsal sclerites of internal sac formed as a long flagellum , then their base not bent laterally. Spermatheca of female, if fusiform, then with distinct apical bulblike enlargement (Fig. 17B Fig. 12G. Male with dorsal sclerites of internal sac formed as a flagellum-like structure apical-ly, abruptly and markedly widened towards rounded basal part . Female with spermatheca short (Fig. 21A), with swollen nodulus. Specimen from the volcanic chain of the Guatemalan Cordillera .......G. antigua sp. n. -Specimen larger (SBL range 1.34-1.51 mm). Habitus as in Fig. 12C. Male with dorsal sclerites of internal sac formed as a wavy, ribbon-like structure (Fig. 13R), of approximately equal width along its entire length. Female with spermatheca elongate, of similar breadth along entire length (Fig. 17F). Specimen from the interior: the Sierra de las Minas range ........G. longinoi sp. n. 8 Pronotum smooth (as in Fig. 1E). Male with dorsal sclerites of internal sac markedly extended basally through basal orifice (Fig. 13A, D) as a long and narrow plate, widened and rounded basally. Female with spermatheca, if fusiform, then also curved (

12.
Pronotum and proepisternum covered with microsculpture. Male with dorsal sclerites of internal sac long, only slightly widened basally (Fig. 19E,H).  Etymology. The specific epithet is a Latinized eponym in the genitive case, and is based on the surname of Robert S. Anderson, Curator of Entomology at the Canadian Museum of Nature, Ottawa, Canada, the collector of the type series of this species.
Recognition. Adults of this new species are distinguished from those of other members of the integripennis species group by the following combination of external characters: size large, elytra wide and smooth (without microsculpture); and males are further distinguished by the size and structure of the median lobe (Figs 9H-J, 10) and the form of the ring sclerite (Fig. 10C).
Legs. Protibia (Fig. 6F). Male genitalia. Median lobe (Fig. 9H) with very long subparallel shaft, and moderately enlarged apex, broadly rounded at tip. Ventral margin slightly convex medially. Dorsal sclerite of internal sac in form of a long plate, apically tapered into a short flagellum, and gradually widened basally with basal margin bent ventrally. Membranous field near ostium flag with numerous small scales. Right paramere with long and narrow apical constriction (Fig. 9J). Left paramere with very long and narrow apical constriction (Fig. 9I). Ring sclerite with handle triangular, rounded apically (Fig. 10C).
Geographical distribution. This species is known only from the type locality in the mountains of the Cerro Huitepec, part of the Chiapas Highlands, State of Chiapas, Mexico (Fig. 22,white diamond).
Way of life. Specimens were extracted from cloud forest litter at an elevation of 2750 m. Recognition. Adults of this new species are practically indistinguishable externally from those of G. zullinii but can be distinguished from the latter and from the other members of the integripennis species group by the structure of the median lobe of males and the shape of spermatheca of females.
Elytra. Moderately convex, slightly depressed along suture, moderately wide (WE/ LE 0.68±0.016), without traces of striae. Humeri broadly rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal third, evenly rounded to apex in apical third.
Male genitalia. Median lobe of aedeagus (Fig. 9E) with long subparallel shaft, and small rounded apex. Ventral margin almost straight. Dorsal sclerites of internal sac in form of a long plate, apically tapered into a rather long flagellum, and abruptly widened basally as a semicircular end plate near basal orifice. Right paramere with long and narrow apical constriction (Fig. 9G). Left paramere with long and narrow apical constriction (Fig. 9F). Ring sclerite with handle triangular, widely rounded apically (Fig. 10B).
Geographical distribution. This species is known only from the type locality in the mountains of the Sierra Madre de Chiapas, located in the municipality of Motozintla, State of Chiapas, Mexico (Fig. 22, white squares).
Way of life. Specimens were collected by sifting oak/pine forest litter at an elevation of 2050 m.
Relationships. Adults of this species closely resemble those of G. zullinii from the Chiapas Highlands externally and in the shape of dorsal sclerites of the internal sac ( Fig. 9E; cf. Fig. 9A). The shape of the spermatheca of females (Fig. 11B) suggests a relationship with the Guatemalan G. integripennis (Fig. 17A) from the Sierra de los Cuchumatanes of the Guatemalan Cordillera. Recognition. Adults of this species (Fig. 8A) are practically indistinguishable from the adults of G. vignatagliantii, described below, and are distinguished from the latter and from the other members of the integripennis species group by structure of the median lobe and shape of spermatheca.

Geocharidius zullinii Vigna Taglianti
Description. The original description provides a thorough accounting of external features of this species and is absolutely sufficient for species characterization. Below, we add references to illustrations of structural features presented here and descriptions of genitalia, which, for females, has not been done previously.
Geographical distribution. This species is widely distributed across the Chiapas Highlands, State of Chiapas, Mexico (Fig. 22, white circles). We have examined a total of 15 specimens (6 males and 3 females dissected) from the following localities: 4 specimens labeled Way of life. Specimens were sifted from litter in a wide range of different forest types (hardwood without oaks, oak, pine and cloud forests) at elevations of 2350-2600 m.
Relationships. The shape of spermatheca (Fig. 11A) of females suggests that this species is closely related to the sympatric G. andersoni (Fig. 11C), described above. Type locality. Guatemala, Sacatepéquez, 5 km SE of Antigua. Etymology. The specific epithet is a noun in apposition and refers to the city in the vicinity of which the type series was collected.

Geocharidius antigua
Recognition. Adults of this new species are practically indistinguishable in body shape from those of other Guatemalan species of Geocharidius with small body size; but the smooth pronotum and presence of microsculpture on the proepisternum form a basis for distinguishing adults of G. antigua from those of sympatric G. minimus and allopatric G. balini, described below. Males and females of G. antigua are distinguished from those of the other members of the integripennis species group by the structure of the median lobe and the shape of spermatheca, respectively.
Microsculpture. Mesh pattern of irregularly isodiametric sculpticells present over all dorsal surfaces of head and elytra. Pronotum smooth. Proepisternum with evident microsculpture.
Elytra. Moderately convex, slightly depressed along suture, moderately wide (WE/ LE 0.67±0.015), without traces of striae. Humeri broadly rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal third, evenly rounded to apex in apical third.
Male genitalia. Median lobe of aedeagus (Fig. 19A) with long subparallel shaft, and small rounded apex. Ventral margin almost straight. Dorsal sclerites of internal sac in form of a long plate, tapered apically as a long flagellum, and abruptly widened basally as a nearly circular complex of structures near basal orifice (Figs 19A-B). Right paramere with short and narrow apical constriction (Fig. 19D). Left paramere with long and narrow apical constriction (Fig. 19C). Ring sclerite with handle triangular, slightly asymmetrical, pointed apically (Fig. 20A).
Geographical distribution. This species is known only from the type locality, situated on the northern slopes of volcano Agua in the volcanic chain of the Guatemalan Cordillera (Fig. 22, yellow quadrangle).
Way of life. Specimens were collected by sifting oak forest litter at an elevation of 2350 m.
Relationships. The shape of dorsal sclerites of the internal sac  suggests that this species is closely related to the Honduran G. disjunctus (Fig. 19Q, T), described below. ence of microsculpture on the pronotum and internally by the structure of the median lobe of males and the shape of spermatheca of females.
Legs. Metatibia (Fig. 7F) Male genitalia. Median lobe (Fig. 13O) with shaft short and broad and apex of moderate size and rounded. Ventral margin greatly enlarged and convex, with numerous poriferous canals. Dorsal sclerites of internal sac of peculiar shape, in form of anastomosing short plates, connected in apical and basal thirds, pointed apically as a short blade. Right paramere long and narrow (Fig. 13Q). Left paramere with long and narrow apical constriction (Fig. 13P). Ring sclerite with handle almost rectangularly rounded, slightly asymmetrical (Fig. 16E).
Geographical distribution. This species is known only from two localities remote from each other: one situated on the southern slopes of volcano Agua in the Suchitepéquez Department, and the other situated on the northern slopes of a former twinned volcano, remains of which form the caldera of Laguna de Ayarza, in Jalapa Department. Both localities are in the volcanic chain of the Guatemalan Cordillera (Fig. 22,  green diamonds).
Way of life. Specimens were collected by sifting cloud forest litter at middle (1600-1750 m) to high elevations (2400 m).
Relationships. The shapes of handle of ring sclerite (Fig. 16E) and of the spermatheca (Fig. 17E) suggest that this species is closely related to G. jalapensis (Figs 16D Type locality. Guatemala, Quiché Department, 7 km NE of Los Encuentros. Etymology. The specific epithet is a Latinized eponym in the genitive case and is based on the surname of Terry L. Erwin, Curator of Entomology at the Smithsonian Institution, United States National Museum of Natural History, Washington, D. C., U.S.A., the first reviser of the Guatemalan Anillina.
Recognition. Adults of this new species are practically indistinguishable from those of other the Guatemalan species of Geocharidius with small body size. Males and females of G. erwini are distinguished from those of the other members of the integripennis species group by the structure of the median lobe of males and the shape of spermatheca of females, respectively.
Geographical distribution. This species is known from a few scattered localities in the Quiché and Quetzaltenango Departments of Guatemala (Fig. 22, green circles).
Way of life. Specimens were collected by sifting litter from different habitats: cloud, hardwood, pine and pine-oak forests at elevations of 2140-2760 m.
Relationships. The shape of dorsal sclerites of the internal sac in males suggests a remote relationship with G. minimus (Fig. 13G), described below. Recognition. Males of this species are distinguished from those of other members of the integripennis species group by the following combination of characters: pronotum small, transverse, elytra comparatively wide and structure of median lobe of male as in Fig. 13A.
Elytra. Moderately convex, slightly depressed along suture, markedly wide (WE/ LE 0.70), without traces of striae. Humeri broadly rounded, in outline forming slightly obtuse angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal half, evenly rounded to apex in apical half.
Male genitalia. Median lobe of aedeagus (Fig. 13A, 15B) with shaft long, widened apically, and apex small and acutely rounded. Ventral margin straight. Dorsal sclerites of internal sac in form of very long plate, protruding from basal orifice, and tapered apically in rather long flagellum, abruptly widened basally as a semicircular dilation, bent ventrally and surrounded by complex of semisclerotized sheaths of peculiar shape. Right paramere with long, narrow apical constriction (Fig. 13C). Left paramere with long, narrow and curved apical constriction (Fig. 13B). Ring sclerite of triangular shape, with sinuations on both sides of long basal handle (Fig. 16A).
Female internal genitalia. Females unknown. Geographical distribution. This species is known only from the type locality in the mountains of the Sierra de los Cuchumatanes, located in the Huehuetenango Department of Guatemala (Fig. 22, white triangle).
Way of life. The unique type specimen was sifted from leaf litter in Lower Montane Wet Forest (Erwin 1982) at an elevation of 2780 m. Relationships. The shape of the median lobe in the holotype of G. gimlii (Fig. 15B) is almost identical to that of the male holotype of G. integripennis (Fig. 15A); hence, at least for now, the latter can be considered as its closest relative. The general shape of the dorsal sclerites of the internal sac (namely the apically tapered plate, widened and ventrally bent at the basal end) is also similar to that in G andersoni (Fig. 9H) males described above. Geocharidius tagliantii Erwin, 1982: 494;synonymized by Zaballos (2004).

Recognition.
Males and females of this species are distinguished from those of other members of the integripennis species group (except G. gimlii, see Relationships above) by the structure of the median lobe of males and the spermatheca of females. Adults of G. gimlii have proportionately much wider elytra than those of G. integripennis.
Elytra. Moderately convex, slightly depressed along suture, moderately wide (WE/ LE 0.67±0.005), without traces of striae. Humeri rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal fourth, evenly rounded to apex in apical third.
Male genitalia. Male genitalia of the lectotype are mounted in old gum, covered now with a network of numerous cracks, making the objects inside hard to see. Hence, we could examine only general shape of the median lobe and could not discern details of the inner sac or of the parameres or the round sclerite. Based on what we could see, the median lobe of the aedeagus (Fig. 15A) is very similar to that of the G. gimlii holotype.
Geographical distribution. Precise locality at which the type series of this species was collected is unknown. Presumably, the material that was collected by Champion and served as the basis for the Bates' description came from the Cerro Maria Tecún mountains in the Totonicapán Department of Guatemala (Fig. 22, black and white triangle), as was shown by Ball and Roughley (1982) for Pterostichus (Percolaus) championi (Bates), the locality label of which is identical with that of the G. integripennis type specimens.
Way of life. The type specimens were collected at an elevation of "10,500 ft." (= 3200 m).
Relationships. Without doubt, the closest relative of G. integripennis is G. gimlii. In view of the similarity in the shape of the median lobes ( Fig. 15B; cf. Fig. 15A) of their males and the range of variation of the median lobes seen among other species of the group, it may seem reasonable to consider these taxa as two subspecies of a single species. However, in the absence of sufficient material for more thorough investigation of variation of the external features and structure of the genitalia, we prefer to preserve the "status quo" and consider G. gimlii and G. integripennis as close, but separate species. Type locality. Guatemala, Jalapa Department, 4 km E of Mataquescuintla. Etymology. The specific epithet is a Latinized adjective in the masculine form based on the name Jalapa, the Department of Guatemala in which the type series was collected.

Geocharidius jalapensis
Recognition. Adults of this new species are distinguished from those of other members of the integripennis species group by the following combination of external characters: size large and pronotum transverse and fully covered with microsculpture. Males and female of G. jalapensis are distinguished from those of other members of the integripennis species group by the structure of the median lobe and the shape of spermatheca, respectively.
Male genitalia. Median lobe (Fig. 13K) with shaft long and apex slightly enlarged and rounded. Ventral margin almost straight. Dorsal sclerites of internal sac in form of a long plate, tapered apically and basally in short extensions . Right paramere with short and rather wide apical constriction (Fig. 13N). Left paramere with long and narrow apical constriction (Fig. 13M). Ring sclerite with almost rectangularly rounded, slightly asymmetrical, handle (Fig. 16D).
Geographical distribution. This species is known only from type locality, situated on the northern slopes of the former twinned volcano, remains of which form the caldera now filled with the waters of Laguna de Ayarza (Jalapa Department). Physiographically, the region is part of the volcanic chain of the Guatemalan Cordillera (Fig. 22, green triangle).
Way of life. Specimens were collected by sifting cloud forest litter at elevations of 2325-2620 m.
Relationships. The shapes of handle of the ring sclerite (Fig. 16D) and of the spermatheca (Fig. 17D) suggest that this species is closely related to G. balini (Figs 13O and 17E), described above. Type locality. Guatemala, El Progreso Department, Cerro Pinalón. Etymology. The specific epithet is a Latinized eponym in the genitive case, and is based on the surname of John T. (Jack) Longino, Professor of the Biology Department of the University of Utah, and one of Co-PI's of the LLAMA project, which provided the material on which the description of this species is based.

Geocharidius longinoi
Recognition. Adults of this new species are distinguished from those of other members of the integripennis species group by the large size, distinctive shape of the pronotum with very wide basal margin, and the proepisternum with evident microsculpture. Males and females of G. longinoi are distinguished from those of other members of the integripennis species group by the structure of the median lobe and the shape of spermatheca, respectively.
Elytra. Moderately convex, slightly depressed along suture, moderately wide (WE/ LE 0.66±0.020), without traces of striae. Humeri rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal forth, evenly rounded to apex in apical third.
Geographical distribution. This species is known only from Cerro Pinalón, part of the Sierra de las Minas range of Guatemala (Fig. 22, green squares).
Way of life. Specimens were extracted from cloud forest litter at elevations of 2000-2750 m.
Relationships. The shape of handle of the ring sclerite (Fig. 16F) and the structure of dorsal sclerites of the internal sac (Fig. 13R) suggest a relationship with the Honduran G. celaquensis (Figs 20B and 19E), described below. Type locality. Guatemala, Sacatepéquez Department, 5 km SE of Antigua. Etymology. The specific epithet is a Latin adjective, minimus (superlative of parvus), in the masculine form, meaning "smallest".

Geocharidius minimus
Recognition. Adults of this new species are distinguished from those of other members of the integripennis species group by the combination of small size, elongate habitus and smooth proepisternum. Males and females of G. minimus are distinguished from those of other members of the integripennis species group by the structure of the median lobe and the shape of spermatheca, respectively.
Geographical distribution. This species is known from the slopes of two volcanos, Agua and Atitlán, in Sacatepéquez and Suchitepéquez Departments of Guatemala, respectively (Fig. 22, green flowers).
Way of life. Specimens were collected by sifting litter in hardwood and cloud forests at middle and high elevations of 1600 and 2200 m, respectively.
Relationships. The shape of dorsal sclerites of the internal sac (Fig. 13G) of males suggests a distant relationship with G. erwini (Fig 13D), described above, whereas the shape of the handle of the ring sclerite (Fig. 16C) of males suggests relationships with the Guatemalan G. antigua (Fig. 20A), described above, and the Honduran G. disjunctus (Fig. 20E), described below.
Recognition. Adults of this new species are distinguished from those of other members of the integripennis species group by their small size, fully microsculptured dorsal body surface and pronotum with wide basal margin. Males and females of G. celaquensis are distinguished from those of the other members of the integripennis species group by the structure of the median lobe and the shape of spermatheca, respectively.
Microsculpture. Mesh pattern of irregularly isodiametric sculpticells present over all dorsal surfaces of head, pronotum and elytra. Proepisternum also with evident microsculpture.
Elytra. Moderately convex, slightly depressed along suture, moderately wide (WE/ LE 0.68±0.015), without traces of striae. Humeri rounded, in outline forming right angle with longitudinal axis of body. Lateral margins convex, evenly divergent at basal third, evenly rounded to apex in apical third.
Male genitalia. Median lobe (Fig. 19E) with shaft subparallel, apex small and narrowly rounded. Ventral margin almost straight. Dorsal sclerites of internal sac in form of long, waved ribbon, tapered apically and slightly dilated and narrowly rounded basally. Right paramere with short apical constriction (Fig. 19G). Left paramere with long and narrow apical constriction (Fig. 19F). Ring sclerite with handle triangular, widely rounded at apex (Fig. 20B).
Geographical distribution. This species is known only from Celaque National Park, part of the Cerro las Minas range of Honduras (Fig. 22, yellow flower).
Way of life. Specimens were extracted from cloud forest litter at an elevation of 2500 m. Relationships. The shape of dorsal sclerites of the internal sac (Fig. 19E) in males and the point of the attachment of the spermathecal gland (Fig. 21B)  that this species is closely related to G. lencanus (Figs 19H and 21C), described below, and perhaps also, but more remotely, to the Guatemalan G. longinoi (Figs 13R and 17F), described above.
Recognition. Adults of this species are practically indistinguishable externally from those of G. disjunctus, described below, and are distinguished from the latter, as from those of the other members of the integripennis species group, by the structure of the male median lobe and the shape of spermatheca in females.
Male genitalia. Median lobe of aedeagus (Fig. 19Q) with shaft long and subparallel, apex small and rounded. Ventral margin straight. Dorsal sclerites of internal sac in form of a long plate, tapered apically into a long flagellum, and abruptly widened basally, with a ventral appendix and pointed semicircular enlargement near basal orifice . Right paramere with long and narrow apical constriction (Fig. 19S). Left paramere with long and narrow apical constriction (Fig. 19R). Ring sclerite with handle triangular, slightly asymmetrical and pointed apically (Fig. 20E).
Geographical distribution. This species is known only from two remote localities in the Honduran Interior Highlands, situated in Yoro and Francisco Morazán Departments. (Fig. 22, yellow triangles).
Way of life. Specimens were collected by sifting cloud and upper montane forest litter at middle to high elevations (1300-2100 m).
Relationships. The shape of dorsal sclerites of the internal sac (Fig. 19Q) of males suggests that this species is closely related to the Guatemalan G. antigua (Fig. 19A)

Discussion
A comprehensive phylogenetic and biogeographic analysis of Geocharidius is postponed until a thorough revision of all species of the genus has been completed. Below we discuss only a few biogeographical and evolutionary issues, raised during our morphological and distributional studies of the integripennis group species.

Biogeographical notes
Distributional records of the integripennis species group to date are represented in Table 1 and can be summarized as follows: The group includes mostly high elevation species: all 15 species live at elevations greater than 2000m, and only four of these also inhabit the 1300-2000m mid-elevation range. Physiographically (Fig. 22), species of the group inhabit the interior mountain ranges of the Chiapas (CH), Guatemalan (SC+MTZ) and Honduran Highlands (HIH) along with the coastal Sierra Madre de Chiapas (SMC) and its continuation as the Guatemalan Cordillera (GC). Geologically, these territories are part of the Maya Block of the North American and the Chortis Block of the Carribean Tectonic Plates, divided by the Motagua (or Motagua-Polochic) Fault Zone (Marschall 2007). The Motagua Fault Zone (Fig. 22, MTZ) has been identified as the most important physiographic barrier in Nuclear Central America, corresponding to many phylogeographic breaks in the distributions of different vertebrate taxa (Perdices et al. 2005, Conchero Pérez et al. 2006Castoe et al. 2009, Daza et al. 2010, Hardy et al. 2013. For Geocharidius species, this zone separates montane areas with higher species diversity (to the south and east) from those with lower diversity (to the north and west). Each of the six montane areas has its own unique assemblage of Geocharidius species, ranging in number from one to six species; and none of these species are shared between montane areas. Consequently, any faunal connections between them are through sister species rather than through conspecific populations; and this pattern has implications for the timing of past dispersal and vicariance events (i.e., suggesting somewhat greater antiquity for such events). As mentioned above, the Motagua Fault Zone is a major physiographic barrier limiting the present distributions of integripennis group species. A second evidently strong barrier is one between the faunas of the Guatemalan Cordillera and the Honduran Interior Highlands, separating the ranges of six and four species endemic to each of these regions, respectively. The headwater valleys of the Rio Paz to the south and Rio Motagua/Rio Shutague to the north, respectively, are linked by gaps in the intervening uplands that do not exceed 900m in elevation, creating a continuous break across these highlands that is 400m lower than the lowest elevations at which any intergripennis species in the region has been recorded.
Among integripennis group members, six species have quite wide ranges within their own montane area, while the other nine species are known from only one locality or from two very close localities (G. longinoi) within their area. Within-group diversity varies markedly between different parts of the region. Four of the six montane areas are inhabited by one or two species, the Honduran Interior Highlands by four species, and the Guatemalan Cordillera volcanic chain (Fig. 22, GC) by six species. Within these areas, such diversity is not based solely on a high number of locally restricted forms. For example, three of the six species of the Guatemalan Cordillera have rather wide ranges for Geocharidius species. This distributional pattern results in three cases of sympatry among the species within the Cordillera. MacVean and Schuster (1981) recorded similarly wide ranges for passalid beetle species and sympatry among them on volcanoes of the Guatemalan Cordillera.
Within the range of the integripennis species group, the Guatemalan Cordillera occupies a special place and can be characterized by the highest number of the species in total, the highest number of species with wide ranges and the highest number of localities in which sympatry has been recorded. This combination of parameters may indicate that, historically, this region played an important role as a staging area for immigrants and as an intersection of dispersal routes of integripennis group species dispersing between different areas.
Two cases of evident similarities in morphology of male and female genitalia between species inhabiting the Cordillera and their relatives outside the region seem to support the above mentioned assertion. The similarity in median lobe structure between the eastern Guatemalan G. antigua (Fig. 19A) and the Honduran G disjunctus (Fig. 19Q) is unequivocal; and presumably homologous structures in the median lobe of males of G. integripennis and G. gimlii (Fig. 15) are virtually identical. This leads us to consider these pairs as sister species. These examples connect the Cordilleran fauna (Fig. 22,GC) with faunas of the Honduran Highlands (HIH) and Sierra de los Cuchumatanes (SC), respectively, thus, supporting our evaluation of the role of the Guatemalan Cordillera as important in the dispersal history of the integripennis group.
Further, certain morphological similarities can be found between the west Guatemalan pair of species, G. gimlii, and G. integripennis, and among the Mexican trio of species, G. andersoni, G. zullinii andG. vignatagliantii. Males of all three Mexican species share a similar shape of the dorsal sclerites of the median lobe (Fig. 9), and a Table 1. Montane areas in Nuclear Central America occupied by the species of the Geocharidius integripennis species group. triangular handle of the ring sclerite (Fig. 10). At the same time, females of G. vignatagliantii can be connected with those of the west Guatemalan G. integripennis by the short, sclerotized, and basally swollen basally spermatheca (Figs 11B, 17A), while the dorsal sclerites of the median lobe of G. andersoni males (Fig. 9H) are somewhat similar to the shortened variant of the dorsal sclerites of G. gimlii males (Fig. 13A).
These examples suggest that the Sierra de los Cuchumatanes (Fig. 22, SC) may have served as an important dispersal route from the Pacific coastal Guatemalan Cordillera northward to the Chiapas Highlands (CH). Given its proximity to the Guatemalan Cordillera, the Sierra Madre de Chiapas (Fig. 22, SMC) would appear to have been a more likely dispersal route northward, but we have no evidence that this route has been used. It is worth noting that, based on morphology, all species of the group living to the north of the Motagua Fault Zone appear to be rather closely related to each other, whereas the species living to the south and to the east of the Motagua Fault Zone appear to represent several morphologically different lineages. Perhaps the Mexican representatives of the group are descendants of a comparatively recent dispersal event involving one of the southern lineages.
Searching for concordant taxon-area relationships in other taxa reveals other carabids with similar distribution patterns. The distribution pattern for species of the pterostichine subgenus Percolaus Bates, as described by Ball and Roughley (1982), is identical to the distribution pattern of the Mexican-west Guatemalan set of Geocharidius' species and encompasses the Chiapas Highlands, the Sierra Madre de Chiapas, Cerro Maria Tecún and Sierra de los Cuchumatanes. Interestingly, these authors suggested that Pterostichus (Percolaus) championi Bates, from the Cerro Maria Tecún has its closest known relative in the Sierra de los Cuchumatanes, the same relationship we see between G. integripennis, presumably collected in the Cerro Maria Tecún, and G. gimlii from the Sierra de los Cuchumatanes. Also, the distribution patterns of three Mexican and one western Guatemalan Geocharidius (namely G. andersoni, G. zullinii, G. vignatagliantii and G. gimlii ) correspond perfectly to the distribution pattern of the species of Platynus jaegeri group (namely P. dilatipes Liebherr, P. robustus (Chaudoir) and P. strictinotum Liebherr (Liebherr 1988).

Sympatric speciation
One common evolutionary trend among Anillina is syntopic miniaturization, a type of sympatric speciation that produces a number of related species differing in size and descendant from a common ancestor (Sokolov 2013). So, comparing average sizes of adults of integripennis group species in localities where sympatry has been recorded presented an interesting test of this idea. As noted above, we recognized six cases of sympatry (Fig. 22) involving the following species pairs (pairs marked by star are syntopic cases): G. andersoni -G. zullinii (Chiapas, Mexico), G. antigua -G. minimus (Volcano Agua, Guatemala), G. minimus -G. balini* (Volcano Atitlan, Guatemala), G. balini -G. jalapensis* (Mataquescuintla, Guatemala), G. lencanus -G. celaquensis* (Celaque National Park, Honduras), and G. comayaguanus -G. disjunctus* (Pico Pijol National Park, Honduras). These pairs of species can be grouped by the number of shared morphological characters into two categories: (1) a group of more closely related species that share two characters of male or female genitalia, namely the shape of the male ring sclerite and the shape of the female spermatheca; and (2) a group of more remotely related species that share only one character from either male or female genitalia. Data on size differences between species in all pairs are presented graphically as box-and-whiskers plots with regression lines (Fig. 23). For all pairs, we recorded the differences in averages of standardized body length between species. Our data support previous observations that the co-occurrence of taxonomically related anilline species in the same habitat is often accompanied by differentiation in their size (body length) (Pérez-Gonzáles andZaballos 2013, Sokolov 2013). Perhaps the persistent (simultaneous) coexistence of two forms (a "larger" and a "smaller" form) in the litter reflects specific adaptations for living in only grossly overlapping microniches, which differ in some unknown parameters of substrate interspaces and thereby harbor different microbiotas. Hypothetically, slight divergence in niche preferences might result in divergence in target food preferences and decrease the number of contacts between representatives of "larger" and "smaller" forms. This, in turn, which could reduce competition between them and allow each to exploit resources more effectively.
At least in some cases, sympatry among anillines is a result of the dispersal of formerly allopatric taxa, typically in response to historical geological events and/or climate change. Interestingly, difference in sizes between a "larger" and a "smaller" species is evidently greater in pairs of more closely related species than in the pairs of more remotely related species. This difference can be seen visually in the slopes of regression lines and the means of the regression coefficients of these lines (Fig. 23, b). Unfortunately, the low number of observations does not allow us to analyze our data statistically and thereby evaluate how significant the observed differences between groups may be. We can only speculate about the origins and significance of differences between the two groups. For the present, we interpret our findings as reflecting differences in historical time at which each case of sympatry developed and, accordingly, by the length of time during which disruptive selection was occurring. We presume that, in the cases of the closely related species, we are dealing with intraspecific divergence, which was continuing for much longer times than in the cases of remotely related species, sympatry among which we consider a result of postspeciation dispersal, and thus of comparatively recent origin. In the latter case, interspecific divergence occurred over a much shorter time period, resulting in lesser differences in size between co-occuring species.
(Collections Manager), Robert S. Anderson (Curator), Robert L. Davidson (Collections Manager), and Terry L. Erwin (Curator) at those institutions, respectively. We thank Terry Erwin (NMHH), Thierry Deuve and Azadekh Taghavian (MNHN) for the loan of types and other specimens under their care. This paper is based in part on material obtained through sampling supported by the National Science Foundation through grant DEB-0640015 (J.T. Longino, R.S. Anderson, P.S. Ward, Principal Investigators). The first author acknowledges the Evert I. Schlinger Foundation for the Schlinger Postdoctoral Fellowship at the California Academy of Sciences in 2012-2014.