A taxonomic revision of the subfamily Tillinae Leach sensu lato (Coleoptera, Cleridae) in the New World

Abstract The subfamily Tillinae Leach is represented by 12 genera in the New World. In this study, eight of these genera are revised. A diagnosis and redescription of the species of Araeodontia Barr, Barrotillus Rifkind, Bogcia Barr, Cylidrus Latreille, Cymatoderella Barr, Lecontella Wolcott & Chapin, Monophylla Spinola, and Onychotillus Chapin are presented. Bogcia oaxacae Barr is designated as a junior synonym of Bogcia disjuncta Barr. One species, Cymatodera striatopunctata Chevrolat, is transferred to Lecontella. The following species are redescribed: Araeodontia isabellae (Wolcott), A. marginalis Barr, A. peninsularis (Schaeffer), Barrotillus kropotkini Rifkind, Bogcia disjuncta Barr, Cylidrus abdominalis Klug, Cymatoderella collaris (Spinola), C. morula Rifkind, C. patagoniae (Knull), Lecontella brunnea (Spinola), L. gnara Wolcott, L. striatopunctata (Chevrolat), Monophylla californica (Fall), M. pallipes Schaeffer, M. terminata (Say), Onychotillus vittatus Chapin, and O. cubana De Zayas. Transcriptions of the original descriptions of Araeodontia picipennis Barr, Bostrichoclerus bicornis Van Dyke and Monophylla cinctipennis (Chevrolat) are given. Cymatodera Gray, with approximately 130 described species, is excluded from this study due to the number of species involved. The genera Neocallotillus Burke and Callotillus Wolcott are also excluded here since these groups have been recently revised elsewhere. Collection data are provided for all species revised. Updated distribution maps are presented. Keys to New World genera and species are given and taxonomic characters of relevant importance are provided and discussed.


Introduction
Cleridae is a family of predatory beetles with a cosmopolitan distribution (Corporaal 1950;Gerstmeier and Weiss 2009, Gerstmeier and Eberle 2011, Opitz 2010. Opitz (2010) has indicated that clerids can be distinguished from other beetle families within the superfamily Cleroidea based on the existence of a postgular plate or postgular process. This plate or process is present in all clerid species, but absent in remaining cleroid families ( Fig. 6A-B). The current classification of Cleridae divides the group in 13 subfamilies (Kolibáč 1997, Opitz 2010, Gunter et al. 2013, with Tillinae the second largest after Clerinae, with approximately 700 described species in 70 genera (Corporaal 1950, Barr 1975, Gerstmeier 2014, Opitz 2010, Burke and Zolnerowich 2016. In the New World, Tillinae is distributed from southern Canada to central South America, including the West Indies ( Fig. 21A-L), and is represented by 12 genera: Araeodontia Barr, Barrotillus Rifkind, Bogcia Barr, Bostrichoclerus Van Dyke, Callotillus Wolcott, Cylidrus Latreille, Cymatodera Gray, Cymatoderella Barr, Lecontella Wolcott & Chapin, Monophylla Spinola, Neocallotillus Burke, and Onychotillus Chapin (Corporaal 1950, Barr 1975, Opitz 2010, Burke et al. 2015, Burke and Zolnerowich 2016. Historically, the description and classification of species within Tillinae have been established on a limited number of external morphological characters, primarily using antennal gestalt, elytral configuration, and overall integument color, with many descriptive works poorly detailed. A number of species within the New World Tillinae are difficult to identify due to intraspecific morphological variation, a situation particularly common for the speciose Cymatodera, where, to date, almost 130 taxa have been described (Burke et al. 2015). A figure that, by itself, represents almost 20% of all described Tillinae species.
In addition, most of the descriptions and keys to species are based on one or a few specimens, and intraspecific variation has not been examined in detail. A revision of the genus represents a major challenge because many species are poorly represented in public and private collections, numerous species are rare in nature, and comparisons with types are particularly difficult due to the rarity and unavailability of this material.

Material and methods
Twenty-two species representing nine of the 12 tillinid genera inhabiting the Americas are treated here. Cylidrus abdominalis Klug, a species that is very likely an introduction from the Old World (Gorham 1876) and is established in Brazil (Corporaal 1950), is redescribed. Material from the monotypic species Bostrichoclerus bicornis Van Dyke, Araeodontia picipennis Barr, and Monophylla cinctipennis (Chevrolat) was not available for study, but the original descriptions are transcribed here. New country records are indicated with an asterisk following the corresponding country.
If more than one male per species was available, and upon permission from the corresponding repository collections or private owners, male genitalia were extracted and dissected from selected specimens. Genitalia extraction and dissection procedures are similar to those outlined by Ekis (1977). Most morphological terminology follows the work of Ekis (1977), Rifkind (1993b) and Opitz (2010). Material was examined with a Leica MZ7.5 stereomicroscope. Images were taken and measured using a Leica DFC 500 digital camera, and stacked using the software Zerene Stacker V. 1.04. Scanning electron photographs were taken using a Hitachi 3500N variable pressure scanning electron microscope.
The following codens refer to public or private collections from which material was obtained and examined: Head subquadrate, conspicuously enlarged throughout its length, as wide as or wider than pronotum; body integument feebly clothed (Figs 3A, 5D) ... Cylidrus -Head not subquadrate, somewhat enlarged throughout its length ( Araeodontia Barr, 1952a Type species. Cymatodera peninsularis (Schaeffer, 1904), original designation. Distribution. Shown in Fig. 21B. Differential diagnosis. Members of Araeodontia can be separated from the similar Cymatodera by the structure of the protarsal claws. The basal denticles of the protarsal claws in Araeodontia are digitiform (Fig. 6E), while members of Cymatodera have these denticles trigonal (Fig. 7B).
Thorax: Pronotum smooth to feebly punctate, widest at middle, sides more constricted behind middle. Prosternum smooth to slightly punctate. Mesoventrite feebly to strongly punctate. Metaventrite slightly punctate, glabrous to conspicuously vested; metaventral process not compressed anteriorly. Metanepisternum concealed throughout its length in lateral view.
Abdomen: Six visible ventrites. Ventrites 1-5 impressed laterally or not. Pygidium of males somewhat differentiated from that of females ; males with sixth ventrite moderately, narrowly V-shaped emarginate (Fig. 16B); pygidium of females simple, broadly rounded (Fig. 16D). Male and female pygidium shape are not variable for all the species in the genus.
Remarks. Barr (1952a) conducted a revisionary work of those Cymatodera species possessing digitiform tarsal denticles (Fig. 6E). In this revision, he indicated that, based on the state of the tarsal denticles, these species should be assigned to a different genus. The tarsal denticles of Cymatodera are triangular (Fig. 7B); however, this character was inconsistent in three species originally assigned to Cymatodera occurring in northern Mexico, Lower California, and the southwestern United States. As a result, the genus Araeodontia was erected and two new species, Araeodontia picta and A. marginalis, were also described. Barr indicated that, based on differences in the structure of the protarsal denticles, Araeodontia could be further divided into two separate groups, one solely composed of A. picta Barr, and the second composed of the remaining species. In this revisionary work, we examined a significant number of specimens from all Araeodontia species, except A. picipennis, and while differences in the size of the protarsal denticles exist, they are subtle and there is not a clear division of two separate groups within the genus (Fig. 1A-D). Araeodontia   1 Elytra immaculate, uniformly brown to dark brown Araeodontia picipennis -Elytra with an array of markings that range from prominent fasciae to maculae, elytral disc light testaceous to dark brown . Integument color of head brown to dark-brown, darker than the rest of the body; two longitudinal fasciae on each elytron, the first located on elytral suture and the second along epipleural fold, these fasciae may be interconnected on elytral apex or not (Fig. 1B)  Elytra with an anterior pair of maculae reaching epipleural fold, these maculae more proximal to the humeri (Fig. 1C) ........... Araeodontia peninsularis -Elytra with an anterior pair of maculae that do not reach the epipleural fold, these maculae are more distal to the humeri (Fig. 1D) .....Araeodontia picta Araeodontia isabellae (Wolcott, 1910) Figs 1A, 18A
Distribution. USA: AZ, CA, NV, TX, UT. Differential diagnosis. Araeodontia isabellae is most similar to A. picipennis. The two species can be distinguished based on the color of the elytral disc and elytral patterning. Araeodontia isabellae has the elytral disc pale testaceous to testaceous and possesses two brown to light brown maculae on each elytron (Fig. 1A), while A. picipennis has the elytra uniformly brown to dark brown and lacks maculae on the elytral disc. Redescription. Male. Form: Somewhat slender, slightly elongate. Color: Head, mouthparts and pronotum light testaceous to brown; thorax, elytra, abdomen and legs light testaceous to testaceous; two longitudinal brown to testaceous maculae on the posterior half of each elytron, the first located proximate to the elytral suture, the second adjacent to the epipleural fold, neither of these maculae reach the elytral apex, these maculae can be faint to almost absent in some specimens (Fig. 1A).
Legs: Vested with short, recumbent setae intermixed with long, erect setae that become more densely arranged on the distal half of the tibia. Femora rugulose; finely punctate. Tibiae transversely rugose, coarsely punctate, vested with short, recumbent setae intermixed with semi-erect setae.
Elytra: Humeri rounded, indicated; sides subparallel; base wider than pronotum; widest behind middle; disc flattened apically; apices subtriangular, very slightly dehiscent; disc convex, surface rugulose; vested, vestiture composed of erect and semi-erect setae; sculpture consisting of small, coarse punctations arranged in striae that are gradually reduced in size behind middle and do not reach elytral apex; interstices smooth, 3.0× the width of punctuation at anterior margin.
Sexual dimorphism: Females can be differentiated from males by the shape of the last abdominal segment. In females of A. isabellae the last abdominal segment is broadly rounded and convex to almost flat; males have this segment broadly and deeply emarginate posteriorly. The structure of the sixth abdominal segment is very consistent for all females examined.
Redescription. Male. Form: Body relatively stout, elongate. Color: Head, anterior margin of pronotum and mouthparts brown to dark brown; pronotum, thorax, elytra, abdomen and legs testaceous to light brown; two brown, longitudinal fasciae on each elytron, the first located on the elytral suture, and extends from anterior margin of elytra and reaches apex, this fascia abruptly reduced in width on second and last fourth, the second adjacent to epipleural fold, and also extends from anterior margin of elytron and reaches apex, this fascia may be reduced to absent on the anterior half of elytral length, both fasciae may be interconnected at the elytral apex (Fig. 1B).
Elytra: Humeri rounded, indicated; sides subparallel, widest behind middle; base wider than pronotum; disc flattened apically; apices subtriangular, slightly dehiscent; disc convex; vestiture composed of stiff, erect and semi-erect setae intermixed with stiff, semirecumbent setae; sculpturing consisting of small, shallow punctations arranged in striae that gradually reduce in size on middle third and do not reach elytral apex; interstices smooth, 4.0× the width of punctuation at anterior margin.
Sexual dimorphism: The female of A. marginalis can be separated from males based on the structure of the last abdominal segment. In females, the lateral and posterior margins of the sixth tergite and the sixth visible ventrite are broadly rounded, making a single semicircular margin; males have the sixth tergite and the sixth visible ventrite subquadrate in shape, and the posterior margin narrowly, shallowly emarginate, the emargination seen in the sixth visible ventrite is slightly deeper than that observed in the sixth tergite. Remaining characters are similar.
Type material not examined. Type locality. Mexico, San Felipe, Baja California Sur, Cape region. Type depository: National Museum of Natural History (USNM).
Distribution. USA: AZ, CA, NM; Mexico: Baja California, Sinaloa, Sonora. Differential diagnosis. Araeodontia peninsularis is most similar to A. picta. Differences in the size and position of the maculae on the elytral disc will help to distinguish these species. The anterior pair of testaceous maculae on the elytral disc of A. peninsularis reach the epipleural fold and these spots are more closely approximate to the anterior margin on the anterior half of the elytral disc (Fig. 1C). The elytral disc of A. picta possesses two maculae that do not reach the epipleural fold, and these spots are more distant from the anterior margin on the anterior half of the elytral disc (Fig. 1D). Additionally, antennomeres 3-10 on A. peninsularis are shorter in length than those found on A. picta.
Redescription. Male. Form: Body somewhat slender, somewhat elongate. Color: Head, pronotum, thorax, abdomen, mouthparts and legs testaceous to light brown, elytra brown to dark brown; mandibles in lateral view brown with posterior half black; two irregular, testaceous maculae on each elytron, the first located on the anterior half, reaching middle third of elytral disc, and the second maculae adjacent to epipleural apex (Fig. 1C).
Legs: Femora rugulose; finely punctate; vested with short, recumbent setae intermixed with long, semi-erect setae. Tibiae longitudinally rugose; rather punctate; vested with short, recumbent setae intermixed with semi-erect setae. Elytra: Humeri indicated; sides subparallel, widest behind middle; base wider than pronotum; disc flattened apically; apices subtriangular, feebly dehiscent; disc convex, vestiture on elytral disc composed of stiff, abundant, semi-erect setae intermixed with less numerous, stiff, semi-recumbent setae and some erect setae scattered throughout elytral disc; sculpturing consisting of deep punctations arranged in regular striae that gradually reduce in size on posterior third and do not reach elytral apex; interstices smooth, 2.5 to 3.0× the width of punctuation at anterior margin.
Sexual dimorphism: Females of this species can be distinguished from males based on the structure of the last abdominal segment. Females have the lateral and posterior margins of the sixth tergite and the sixth visible ventrite broadly rounded, forming a single semicircular margin ( Fig. 16C-D). Males have the sixth tergite and the sixth visible ventrite subquadrate in shape, and the posterior margin narrowly, shallowly emarginate, the emargination observed in the sixth visible ventrite is somewhat deeper than in the sixth tergite ( Fig. 16A-B). Remaining characters are similar for both sexes.
Female: Medium size, somewhat elongate; piceous; pronotum faintly paler at sides and across middle; elytra with brownish subapical spots, right elytron with a broad, faintly indicated, brownish ante-median area along lateral margin at middle; undersurface dark testaceous. Head finely, somewhat sparsely punctured, finely wrinkled at base, sparsely clothed with short, erect brownish hairs; front feebly bi-impressed; antennae brown, stout, reaching basal fourth of elytra, second segment two-thirds as long as third, third segment slightly longer than fourth, segments 5 to 10 nearly equal in length, longer than those preceding, cylindrical, outer margin of each of these segments broadly rounded, slightly incrassate at apex. Pronotum one-third longer than basal width; surface finely, sparsely punctured, sparsely clothed with short, fine pale hairs, intermixed with moderately long, erect brown hairs; ante-scutellar impression wanting. Elytra two and one-half times longer than basal width, nearly twice as wide as pronotum at base; humeri distinct; sides widest behind middle; apices nearly conjointly rounded; surface with striae consisting of fine punctures, extending to subapical spots, interspaces much wider than punctures, sparsely clothed with short, suberect pale hairs. Legs dark testaceous, piceous at apices of femora and bases of tibiae, finely, densely punctured, densely clothed with short, brown hairs; middle tibiae dark. Metaventrite finely and very sparsely punctured. Abdomen finely, densely punctured; fifth sternite rounded at apex, deeply incised at middle; sixth sternite semicircular in shape; sixth tergite longer and broader than sixth sternite, narrowly rounded at apex. Length: 7 mm.
Holotype, female (C. A. S. No. 5622) from Venancio, July 17, 1938, collected by Michelbacher and Ross. C. picipennis belongs to the Xanti group in Wolcott's key and will run to C. tuta Wolcott and C. laevicollis Schaeffer. It may be separated from these two species by the dark piceous color with the brown, subapical elytral spots and by the structure of the antennae. This species is described from a single female which is in a somewhat damaged condition, the left antenna is broken off at the fourth segment, one of the hind legs is missing, and several of the tarsi are gone. However, the critical characters are present and the species appears to be sufficiently distinct to warrant a name at this time. Remarks. Barr (1952a), in his revision of the genus Araeodontia, stated that this species is restricted to an area in the vicinity of San Venancio, Baja California Sur, Mexico, and it is only known from the female holotype. Barr indicated that A. picipennis is most similar to A. peninsularis; however, the two species can be differentiated by the structure of the tarsal claws and the elytral disc pattern; specifically, in A. picipennis, the two inner tarsal denticles are slender and closely approximated and the elytral disc is immaculate, in a pale testaceous tone. In A. peninsularis, the tarsal denticles are thicker and distinctly separated, and each elytron has two irregular testaceous maculae, the first located on the anterior half, reaching the middle third of elytral disc, and the second maculae adjacent to epipleural apex. Barr pointed out that the validity of the species is questionable and perhaps its rarity is due to its close resemblance with A. peninsularis, with the holotype possibly just a case of the maculae being absent. If so, A. picipennis would be treated as a junior synonym of A. peninsularis. Barr, 1952a Fig. 1D Paratypes. Two females examined.
Distribution. Mexico: Chihuahua. Differential diagnosis. Araeodontia picta is most similar to A. peninsularis. The two species can be reliably separated based on the maculae on the elytral disc. The anterior pair of testaceous maculae of A. picta are well separated from the anterior margin of the elytral disc and do not reach the epipleural fold (Fig. 1D); these spots are noticeably closer to the anterior portion of the elytral disc in A. peninsularis and are in partial or total contact with the epipleural fold (Fig. 1C).
Redescription. Female. Form: Body relatively slender, feebly elongate, similar in shape to remaining Araeodontia species. Color: Head, pronotum, thorax, abdomen, mouthparts and legs testaceous to light brown, elytra brown to dark brown; mandibles black; two irregular testaceous maculae on each elytron, the first located on middle of elytral disc, the second adjacent to epipleural apex (Fig. 1D).
Aedeagus: Not available. Sexual dimorphism of this species is provided in the original description given by Barr (1952a) Remarks. Barr (1952a), in his revisionary work of Araeodontia, described A. picta as a new species endemic to the southern portion of Chihuahua, Mexico. In the type material revised by him, he indicated the existence of a single male, in this case, the holotype. Remaining specimens in the type series are females. The species is particularly uncommon in most collections; consequently, it was impossible to obtain males for this revisionary work. For that reason, the female paratype was redescribed.
Distribution. Shown in Fig. 21C. Differential diagnosis. This monotypic species is most closely allied to members of Neocallotillus, with a particular resemblance to Neocallotillus elegans. A number of characters are useful to separate these species: Barrotillus kropotkini has the antennae composed of 11 antennomeres with the segments moderately serrate ( Fig. 1E; 8B), the anterior portion of the pronotum is strongly constricted posteriorly, and the pronotal disc is coarsely and deeply punctate (Fig. 7D). Neocallotillus elegans has the antennae with 10 antennomere which are pectinate in males ( Fig. 8D-E) and serrate in females ( Fig. 8-F), the pronotal disc is somewhat constricted posteriorly (Fig. 2B), and the punctations on the elytral disc are shallowly and slightly impressed.

Barrotillus kropotkini
Redescription. Male. Form: Body elongate, slender, small size, 5.3 mm. Color: Head, dorsal portion of pronotum, elytra, abdomen, legs and labial palpi piceous; ventral and posterior portion of pronotum, prosternum, mesoventrite, labrum, mouthparts and posterolateral portion of metaventrite rufous, antennae dark-brown; each elytron with one macula and one fascia, both markings white and raised from elytral surface, the macula is located on the median region of the anterior third of the elytral disc and the fascia is located on the median region of the elytral disc, the fascia begins on the epipleural fold and do not reach the elytral suture (Fig. 1E).
Elytra: Humeri indicated, slender, elongate, subparallel, slightly broader on posterior third, convex on anterior third, then moderately compressed in middle third, and conspicuously convex again in posterior third, sinuosity observable on lateral view, sculpturing consisting on shallow punctations irregularly arranged, punctations extending to apex, elytral apices rounded, feebly dehiscent, interstices at elytral base about 2.5× the width of punctation; scutellum subquadrate, profusely vested with fine, recumbent and long setae, not compressed; epipleural fold compete, narrowing toward apex.
Aedeagus: Not available. Sexual dimorphism: Rifkind (1996) indicated the presence of antennal differences between the male and the female of this species. The eleventh antennomere of the female is somewhat shorter than that of the male; also, in the female, this segment is not medially compressed. Additional differences between males and females are seen in the sixth sternite, where females have the posterior margin of this segment complete and rounded, rather than notched, as observed in males.
Remarks. Rifkind (1996) mentioned the close resemblance this genus has with many species of Stenocylidrus Spinola, checkered beetles restricted to the Afrotropical region and some Australasian islands. Rifkind further indicated that the campanulate state of B. kropotkini is similar to certain species of Cladiscus Chevrolat, Pseudopallenis Kuwert and Eburneocladiscus Pic, those genera occurring in the tropical regions of Africa and Madagascar. In the New World, Barrotillus kropotkini is most closely allied to Neocallotillus. The campanulate state of the pronotum of this species can be considered a homoplasy shared with many tillinids, rather than an indication of relatedness.
Bogcia Barr, 1978 Type species. Bogcia disjuncta Barr, 1978, original designation. Distribution. Shown in Fig. 21D.  (Fig. 4F). The two species can be readily distinguished based on differences in the structure of the protarsal claw and the antennae. Bogcia disjuncta has the protarsal denticle in close proximity to the protarsal claw ( Fig. 7A) and the antennae is strongly serrate (Fig. 8C). Cymatodera bogcioides has the protarsal claw conspicuously separated from the protarsal denticle ( Fig. 7B) and the antennae is moderately serrate.

Bogcia disjuncta
Redescription. Male. Form: Rather robust, moderately wider posteriorly, elongate. Color: Head, antennae, mouthparts, thorax legs, elytra and abdomen testaceous to brown; posterior half of mandibles black 2-3 irregularly fuscous. Each elytron with a broad, black to brown oblique fascia located behind median region of elytron with varying degrees of extension, ranging from the epipleural fold to the elytral suture, to two reduced, dark maculae, this fascia is preceded by a narrow, pale region; in addition to the dark fascia there is one small, brown to black humeral macula, this spot is absent in some specimens examined (Figs 1F,2A).
Head: Measured across eyes wider than pronotum; surface rugose; frons feebly biimpressed; coarsely punctate; eyes medium-sized, somewhat rounded, inconspicuously longer than wide, emarginate in front, bulging laterally, separated by approximately 2.5 eye-widths; antennomeres 2-3 very slightly serrate; third antennomere about 2× the length of second antennomere; fourth antennomere as long as third antennomere; antennomeres 4-10 strongly serrate, about the same length, as broad as long, posterior distal angle sharply pointed; eleventh antennomere about the same length as the tenth antennomere, with its distal margin moderately oblique (Fig. 8C).
Sexual dimorphism: Females differ from males by having the posterior margin of the first and second visible ventrites truncate (Fig. 7E), and not acuminate (Fig. 7F) as observed in males. Additionally, females have the fifth visible ventrite rugose, with the lateral margins oblique and the posterior margin truncate; the sixth visible ventrite is rugulose, semicircular in shape, with the surface convex, and the lateral and posterior margins broadly rounded; the fifth tergite is rugulose, the lateral margins are oblique and the posterior margin is truncate; and the sixth tergite is rugulose, broader than long, with the surface inconspicuously convex, and the lateral and posterior margins strongly oblique and slightly acuminate posteriorly.
Remarks. Interspecific variation in integument color and fasciae arrangement is a very common condition among numerous clerid species, and various descriptive works (Wolcott 1909, 1921, Rifkind 1993b, Leavengood 2008, Rifkind et al. 2010Burke 2013, Burke and Zolnerowich 2014, 2015 have shown that abdominal and aedeagal differences are the most reliable morphological characters used for delineating interspecific boundaries within Cleridae. Barr (1978) described Bogcia disjuncta and B. oaxacae from the Pacific coast of Mexico, designating B. disjuncta as the type species. Differences in integument color and fascia pattern were the principal characters used by Barr to separate these species. The integument color and fasciae pattern from specimens examined here and identified as B. disjuncta and B. oaxacae, including one male and one female paratype of B. oaxacae, were highly variable and many intermediate forms were observed (Figs 1F,2A). Additionally, the aedeagal and pygidial structures of these individuals were very similar and consistent ( Fig. 18D-E). Consequently, the characters provided by Barr to separate these species are not sufficient to retain them as separate entities, and we designate B. oaxacae as a junior synonym of B. disjuncta.
Distribution. Shown in Fig. 21E. Type locality. Palm Cañon, Angel de la Guardia, Golf of California, Mexico. Type depository: California Academy of Sciences (CASC).
Distribution. USA: CA; Mexico: Baja California. Due to the rarity of the species, this unusual clerid was not examined in this revisionary work; however, in order to complement the revision of the Tillinae in the New World, the descriptive work of Van Dyke (1938) is given here.
Differential diagnosis. The species is most similar to Cymatodera. It, however, does not look like any species of the latter genus, but at first sight rather like a large species of the genus Polycaon of the family Bostrichidae, also because of its size and general appearance somewhat suggests Natalis [Cleridae: Clerinae]. Its distinctive peculiarities are the prominent horns, the type of antennae and the glabrous elytra.
Description. Large, elongate, very finely and sparsely pilose. Head large; eyes large, transverse, coarsely granular, feebly emarginate in front, and very prominent; antennae long, 11 segmented, scape robust, segments 2-5 about twice as long as broad, feebly clavate and quite glabrous, a few stiff hairs only being evident, segments 6-10 moderately serrate, eleventh fusiform, the free angles of 6-8 densely clothed with fine silky pile and the three following segments completely clothed; a prominent horn, laterally compressed and bifid at apex, arising from in front of each eye and just within the insertion antennae giving the latter the appearance of arising from their base; mandibles robust; maxillary palpi four segmented, labial palpi three segmented, the terminal segments of both sets securiform, that of the labial palpi the larger, and almost an equilateral triangle. Prothorax robust, somewhat longer than broad, broadly constricted at sides in front of middle and narrowed posteriorly, basal margin a complete and well defined bead; coxal cavities rounded and narrowly opened behind. Elytra almost 3× as broad as prothorax, two and a half times as long as broad. Finely, densely and irregularly punctured and without striae except for fine sutural striae close to the suture and extending from about the middle almost to the apex. Anterior coxae conical, very narrowly separated, trochantine not visible; middle coxae somewhat conical well separated and with evident trochantine; hind coxae transverse. Abdomen with five free ventral segments. Legs long and slender; tibiae with short terminal spurs; tarsal segments all well developed, flattened dorsally, 1-4 broad yet longer than broad, with usual membranous appendages and densely papillose beneath, the fifth with sides somewhat papillose; claws simple. Van Dyke, 1938. Description. Holotype: unique from Palm Cañon, Angel de La Guardia Island, Gulf of California, collected May 3, 1921, by J. C. Chamberlin, from beneath bark. Moderately large, dark brown and somewhat shining. Head flattened in front, densely punctured above, smooth and sparsely punctured anteriorly, with a faint medial, longitudinal impression on front and sparsely pilose. Prothorax about a sixth longer than broad, base lobed at middle and sinuate each side, apex broadly arcuate and overhanging, disk irregularly punctured, more closely and deeply so in front and with short, reclinate hairs widely scattered about, and broadly and feebly impressed at middle. Scutellum semicircular, densely punctured, rugose and concave. Elytra convex, with pronounced though well rounded humeri, sides almost parallel and disc somewhat dull as the result of the dense punctations and fine rugoseness. Beneath somewhat shining, densely punctured anteriorly and sparely behind. Legs with apices of tibiae beneath and undersurfaces of the tarsal segments from 1-4 densely clothed with short, silky, orange pile. Length 20 mm. with head flexed, breadth 6.5 mm.

Remarks.
Bostrichoclerus is remarkably different from other tillinid species in the New World. Van Dyke (1938) indicated that, based on the coarsely faceted structure of the eyes, the genus should be placed within Tillinae. He thought Bostrichoclerus was closely related to Cymatodera, but Bostrichoclerus is very different from all known forms of Cymatodera. According to Van Dyke, Bostrichoclerus bicornis is easily identified based on the prominent frontal horns, the shape of the antennae, and the completely glabrous elytral disc. Bostrichoclerus bicornis was described based on single specimen collected in Isla Angel de la Guardia in the Golf of California, Baja California, Mexico. Later on, a second specimen was collected in southern California (Barr 1957 Differential diagnosis. Member of Cylidrus can be separated from remaining New World Tillinae species by the structure of the head (Figs 3A, 5D) and antennae (Fig. 8G). No other tilline in the New World has the head subquadrate in shape and conspicuously enlarged, the frons as wide as the total pronotal width, and the antennomeres 5-11 or 6-11 expanded and compressed laterally (Fig. 8G).
Redescription. Size: 5-15 mm. Color: Light testaceous to black, fasciae on elytral disc absent or present, if present of various sizes and shapes. Body: Subparallel, elongate, robust to slender.
Elytra: Elongate; subparallel; inconspicuously widest behind middle; surface shiny to feebly punctate, punctations may extend to posterior third but never reach apex; scutellum ovoid, not compressed; vested to devoid of vestitures; epipleural fold complete, narrowing toward apex.
Abdomen: Six visible ventrites. Ventrites 1-5 impressed laterally or not; pygidium of males slightly differentiated from that of females; males with sixth ventrite emarginate or not; sixth ventrite of females simple, broadly rounded to rather subquadrate (Fig. 16D). Male and female pygidium shape similar.  Gorham (1876) indicated that C. fasciatus was introduced to South America and eventually became adapted to this new habitat. The five Brazilian specimens of C. abdominalis examined here do not differ from C. fasciatus, a finding contrary to Gorham's observations on elytral fasciae differences be- tween these two entities. The fasciae observed in individuals examined under the name C. fasciatus display slight differences in shape, color, and pattern (Figs 3A, 5D). These fasciae can range from dark testaceous to almost albus, and can extend from the elytral suture to the epipleural fold, to only a pair of spots on the median region of the elytral disc. Specimens of C. abdominalis examined here are consistent with this variation. Remaining characters were not variable for material of both species.
Aedeagus: Not available. Remarks. Cylidrus Latreille is composed of 19 species and seven subspecies distributed in the tropical regions of Africa and Oceania (Corporaal 1950). Gorham (1876) indicated that Cylidrus abdominalis is most similar to the African C. fasciatus and was probably transported from the Old World and became established in Brazil. Cylidrus abdominalis is here redescribed from material collected in the southeastern Brazilian provinces of Espirito Santo, Mato Grosso do Sul and Santa Catarina. Irrespective of its origin, whether a natural occurrence or an introduced species, the material examined here confirms the existence of this genus in the New World.
Distribution. Shown in Fig. 21H. Differential diagnosis. Cymatoderella is most similar to various Cymatodera species of moderate dimensions. The two genera can be recognized based on the size of the ommatidia. Cymatoderella species have the diameter of the ommatidia somewhat small (Fig. 6F) compared to Cymatodera species (Fig. 12A). Additionally, the bicolored composition of the integument in Cymatoderella, with a testaceous to ferrugineous coloration on the head and pronotum and a piceous tone on the rest of the body (Fig. 3B-D) will serve to separate these genera. Cymatodera bicolor (Say) is the only species in the genus with a similar color pattern, but it has an elongate and narrow body shape (Fig. 5E), not a robust one, as observed in Cymatoderella (Fig. 3B-D).
Redescription. Size: 3-7 mm. Body: Small, relatively robust individuals. Color: Pronotum bicolored, testaceous to ferruginous in the median region and piceous on the margins to uniformly testaceous to ferruginous; legs, antennae, thorax, elytra and abdominal segments piceous; head and mouthparts can be testaceous, ferruginous, or with an array of piceous tones; for C. patagoniae, visible ventrites 4-6 can be testaceous to ferruginous. Form: Small sized individuals, body short, robust, elytra subparallel to moderately expanded posteriorly.
Remarks. Cymatoderella was established by Barr (1962) to separate Tillus collaris Spinola and T. patagoniae Knull, two New World species, from Tillus (Olivier), a widely distributed genus with a concentration of species in Africa and Oceania. Later on, Rifkind (1993a) described a third species, Cymatoderella morula. Cymatoderella collaris is widely distributed throughout North and Central America; the species ranges from the eastern and southern United States, extending southward to Mexico and the Central American countries of Guatemala, Honduras and El Salvador. Cymatoderella morula and C. patagoniae are species with a limited distributional range. Cymatoderella morula inhabits regions of southern Mexico, Guatemala, Honduras, and Nicaragua (Rifkind 1993a), and C. patagoniae is found in southern Arizona and Guerrero, Michoacan and Sonora, Mexico. Barr 1 Last abdominal segment ferruginous, remaining abdominal segments testaceous to almost piceous; elytral disc conspicuously clothed with pale, short, semirecumbent setae (Fig. 3D) (1) Antennomeres 2-4 subequal in length, short, cylindrical; antennomeres 5-10 robust, moderately serrate (Fig. 9D) Differential diagnosis. Cymatoderella collaris is most similar to C. morula. The two species can be differentiated based on the structure of the antennae. Antennomeres 2-4 of C. collaris are short, cylindrical and subequal in length, and antennomeres 5-10 are elongate, robust and moderately serrate (Fig. 9D). In contrast, Cymatoderella morula has antennomeres 2-3 short, cylindrical and subequal in length, and antennomeres 4-10 elongate, robust and moderately serrate (Fig. 9E). The geographic distribution of these species may also serve to differentiate them; C. collaris is widely distributed from the eastern and southern USA south to El Salvador, while C. morula is found in southwest Mexico, Guatemala, Honduras and Nicaragua.

Key to species of Cymatoderella
Redescription. Male. Form: Body short, robust, elytra gradually expanded toward apex, then abruptly narrowing behind distal fourth. Color: Pronotum uniformly testaceous to ferruginous throughout its surface to bicolored, if bicolored, ranging from testaceous to ferruginous in the median region and piceous on the margins; legs, antennae, thorax, elytra piceous; abdomen piceous to dark testaceous; head and mouthparts with various of piceous tones. Elytral disc devoid of any bands or fasciae (Fig. 3B).
Thorax: Pronotum bisinuate, widest at middle; sides constricted subapically, more strongly constricted behind middle, slightly constricted in front of middle; surface shiny, smooth, vested with fine, long pale, semirecumbent setae intermixed with some long semierect, fine, pale setae; in some individual vestiture is more abundant on the posterolateral area of the pronotum; finely punctate; punctations small and shallow; anterior transverse depression and subbasal tumescence absent, abruptly compressed on posterior margin. Prosternum conspicuously wider than long; smooth; polished, devoid of punctation in most individuals, some specimens very feebly punctate, punctations coarse and shallow; vested with fine, pale, semi-erect setae. Mesoventrite shiny, smooth, vested with fine, pale, semi-erect setae. Metaventrite strongly convex, surface shiny to finely rugulose, inconspicuously vested with fine, pale, recumbent setae; longitudinal depression and metaventral process present. Metepisternum hidden throughout its length. Scutellum ovoid, compressed medially, clothed with pale, fine, recumbent setae to glabrous.
Sexual dimorphism: Females of C. collaris can be distinguished from males based on the shape of the last abdominal segment. Females have the sixth visible ventrite conspicuously long and broad, appearing as a semicircle, rather than short, subtriangular in shape, and broadly and shallowly emarginate posteriorly, as observed in males. Remarks. After examination of material of Cymatoderella collaris, we observed that the morphology of this species is generally consistent throughout its geographical range. Certain characters, however, may vary in accordance to the collecting locality; this variation is apparent when comparing material collected in southeastern USA and the Florida peninsula with specimens collected elsewhere. Such variation is observable in the integument color of the abdomen of both sexes. Material collected in the southeastern USA and the Florida peninsula have the abdomen uniformly piceous; while those individuals collected in the mid-southern USA, Mexico and Central America have the abdomen moderately fuscous to dark testaceous. Remaining characters were constant for all individuals studied.
Distribution. Mexico: Oaxaca; Central America: Guatemala, Honduras. Differential diagnosis. Cymatoderella morula is most similar to C. collaris. Characters to distinguish these species appear in the diagnosis section of C. collaris.
Redescription. Male. Form: Small and robust individuals, elytra gradually expanded toward apex, then abruptly narrowing behind distal fourth. Color: Pronotum uniformly testaceous to ferruginous throughout its surface to bicolored, if bicolored, can range from testaceous to ferruginous in the median region and piceous on the margins; legs, thorax and elytra piceous; abdomens dark testaceous; antennae uniformly piceous, or with scape and pedicel dark testaceous to piceous and remaining antennomeres piceous; head and mouthparts with various tones of piceous to brown tones. Elytral disc devoid of any bands or fasciae (Fig. 3C).
Elytra: Broader than pronotum; broader than long; humeri indicated, rounded; sides subparallel, gradually broadening toward distal end; broadest behind middle, then abruptly narrowing toward apex behind posterior third; disc flat above; surface shiny, smooth; elytral apices subtriangular; inconspicuously dehiscent; elytral declivity moderately steep; surface clothed with fine, short, pale, recumbent setae interspersed with some scattered pale, fine, long, erect setae; surface strongly, coarsely punctate; sculpturing consists of coarse, deep, punctations arranged in regular striae that gradually reduce in size toward elytral apex and completely disappear on posterior fifth; interstices at elytral base about 2× the width of punctation; interstices shiny, smooth.
Legs: Femora shiny, smooth, swollen, anterior femora conspicuously more swollen than middle and posterior femora; clothed with some pale, fine, semirecumbent and semi-erect setae; tibiae feebly rugulose, vestiture similar to that observed on femora, some specimens have tibiae more strongly vested than femora.
Sexual dimorphism: Females of C. morula can be distinguished from males based on the shape of the last abdominal segment. Females have the sixth visible ventrite broadly rounded posteriorly, rather than subtriangular in shape and broadly, shallowly emarginate, as observed in males. Distribution. USA: Arizona; Mexico: Guerrero*, Jalisco, Michoacan*, Morelos, Sonora. Differential diagnosis. Cymatoderella patagoniae can be differentiated from congeners based on the color of the pygidium and the elytral vestiture. Cymatoderella patagoniae has the pygidium testaceous to ferrugineous (Fig. 17C-D), and the elytral vestiture is pale to whitish, fine and recumbent (Fig. 3D); on the other hand, C. collaris and C. morula have the last abdominal segment brown to almost black, and the elytral disc is clothed with pale, yellowish to testaceous, semirecumbent setae interspersed with some semierect setae.
Sexual dimorphism: Females have the sixth visible abdominal segment broadly rounded posteriorly, rather than broadly, shallowly emarginate, as observed in males. Remarks. Rifkind (1993a) examined material identified by him as C. patagoniae that was collected in the western portion of the Mexican state of Jalisco. We compared one of those specimens with the extensive type series Knull (1946) designated as C. patagoniae and this specimen matches Klug's original description. Rifkind (pers. comm.) also mentioned that material of C. patagoniae has been collected from the Mexican states of Guerrero and Michoacan. Finally, Toledo et al. (2014) reported the existence of this species in the state of Morelos. Consequently, the geographic range of this species is extended to central Mexico.
Distribution. Shown in Fig. 21I. Differential diagnosis. Lecontella resembles various members of Cymatodera, but it can be differentiated from species of this genus if the elytral punctations are coarse, deep, and extending to the elytral declivity (Figs 3E-F, 4A, 7G, 12 C, E-F), and the antennae are moderately serrate with antennomeres 2-10 feebly to conspicuously compacted (Figs 9F, 10A-B). Species of Cymatodera, on the other hand, have the elytral disc moderately punctate, the striae almost never reach the elytral apex (Figs 4F, 5E, 13C-D), the antennal shape ranges from filiform to variously serrate, and antennomeres 2-10 are not compacted (Figs 10G-H).
Redescription. Size: 8-28 mm. Color: Body uniformly fuscous to testaceous except abdomen, slightly lighter than rest of the body, integument can range from brown-testaceous to almost ferrugineous in some individuals. Elytral disc with fasciae or maculae absent. Body: Winged species, body elongate, somewhat robust.
Remarks. Wolcott and Chapin (1918) established the genus Lecontella, designating Lecontella (Cymatodera) cancellata (LeConte) as the type species; subsequently, L. cancellata was synonymized by Ekis (1975) with L. brunnea (Spinola). The genus is currently composed of two species: Lecontella brunnea (Spinola), a species originally described as Cymatodera longicornis var. brunnea by Melsheimer (1846), later on transferred to Lecontella by Wolcott and Chapin (1918) and the current type species for the genus, and L. gnara Wolcott, 1927. Based on an extensive examination of material identified as Cymatodera striatopunctata Chevrolat, a third species is designated to Lecontella in this revision. This change is based on the close similarities on elytral punctations (Fig. 4A), antennae (Fig. 10B), and aedeagus (Fig. 20A) of C. cancellata with L. brunnea (Figs 3E,9F,19E) and L. gnara (Figs 3F, 10A, 19F). Mawdsley (2002) has indicated that the larvae of L. brunnea can be parasites in nests of solitary bees and wasps. Additionally, immature stages of L. brunnea were observed preying on larvae of wood-boring species of the Cerambycidae and Buprestidae families. Adults of Lecontella species are commonly attracted to lights.

1
Punctations on pronotal disc coarse, deep and wide (Fig. 12F)   Differential diagnosis. Lecontella brunnea is most similar to L. gnara. The two species are partially sympatric but can be differentiated based on the structure of the pronotal punctations and the antennae. The pronotal punctations on L. brunnea are conspicuously numerous and small (Fig. 12E), while in L. gnara these punctations are scarce, coarse, deep and broad (Fig. 12F). In addition, antennomeres 3-5 of L. brunnea are somewhat slender, moderately compacted and serrate, serration increasing toward the distal end (Fig. 9F); on the other hand, specimens of L. gnara have the antennomeres 3-5 somewhat robust, compacted, and feebly serrate (Fig. 10A).
Sexual dimorphism: Females of L. brunnea can be differentiated from males based on differences on the last abdominal segment. In females the eleventh antennomere is broadly rounded, while in males this antennomere is somewhat triangular in shape, with the lateral margins moderately to strongly oblique, and the posterior margin short and V-shaped emarginate. In addition, females have the eleventh antennomere short, slightly robust, rounded, and longer than the tenth antennomere, while males have the last antennomere cylindrical, not compressed medially and conspicuously longer than tenth antennomere.  Wolcott, 1927 Figs 3F, 7G, 10A, 12C, F, 19F Synonyms. Cymatodera cilindricollis Spinola, 1844, nec. Chevrolat 1833. "Mexique" Synonymized by Ekis (1975).
Distribution. USA: AZ, CA, NM, NV, TX, UT; Mexico: Baja California, Sonora. Differential diagnosis. Lecontella gnara is most closely related to L. brunnea. Characters to distinguish these species are given in the diagnosis section of L. brunnea.
Elytra: Broader than pronotum; elongate; humeri indicated, rounded; sides inconspicuously broadening toward distal end, broadest on posterior third, then abruptly narrowing toward apex at posterior fourth; disc flat above; surface rugose to rugulose at interstices; elytral apices subtriangular; inconspicuously dehiscent; elytral declivity moderately steep; surface vested with fine, short, pale, recumbent setae interspersed with some pale, fine, long, erect setae; conspicuously, coarsely punctate, punctations consisting of coarse, deep, wide punctations arranged in regular striae of the same size that decrease in size at elytral declivity, punctation reach the elytral apex (Fig. 7G); interstices at elytral base as wide as the width of punctation; interstices smooth. Epipleural fold gradually narrowing toward apex, last sixth moderately crenulate.
Sexual dimorphism: Females of L. gnara can be differentiated from males based on the shape of the last abdominal segment. The sixth visible segment in females is broadly rounded, while males have this segment somewhat subquadrate with the posterior margin broadly, very shallowly emarginate. In addition, females of L. gnara have the eleventh antennomere short, somewhat robust and longer than the tenth antennomere; males, on the other side, have the last antennomere cylindrical, not compressed medially and conspicuously longer than the tenth antennomere. Differential diagnosis. Lecontella striatopunctata is most similar to L. brunnea. The two species are parapatric in distribution and can be misidentified as each other; however, males of L. striatopunctata have the antennomeres 2-10 conspicuously compacted and robust, and the eleventh antennomere is 3-4× the length of tenth antennomere (Fig. 10B). Males of L. brunnea have the antennae compacted, antennomeres 3-10 gradually increasing in width toward the distal end, and the eleventh antennomere is 4-5× the length of the tenth antennomere (Fig. 9F). Males and females of these species can also be differentiated based on the shape of the epipleural fold. Lecontella striatopunctata has the posterior portion of the epipleural fold smooth, while L. brunnea has the same portion of the epipleural fold moderately crenulate.
Distribution. Shown in Fig. 21J. Differential diagnosis. Monophylla is conspicuously different from other New World tillinids, and several morphological characters are unique to this genus. The most characteristic feature of the genus is the size of the last antennomere. Species in Monophylla have this antennomere conspicuously longer than remaining antennomeres combined (Fig. 10C -D). This character state is also observed in species of the African genus Teloclerus Schenkling (Cleridae: Tillinae). The enlarged and feebly emarginate eyes of Teloclerus (Fig. 4E) may serve to separate this genus from the New World Monophylla, where the eyes are of moderate size and conspicuously emarginate, almost dividing them into two portions (Fig. 12B). Additional characters that will serve to separate Monophylla from other New World Tillinae genera are the rectangular shape and strongly rugulose surface of the pronotum (Fig. 7C), and the exposed pygidium in dorsal view (Fig. 4C-D).
Head: Including eye slightly narrower than pronotum; integument numerously, coarsely punctate, punctations vary from narrow to wide and shallow to deep; eyes moderately small, finely faceted, strongly emarginate, emargination almost dividing each eye into two separate halves (Fig. 12B); inconspicuously bulging laterally; number of antennomeres variable, last antennomere as long as or conspicuously longer than the length of remaining antennomeres combined ( Fig. 10C-D); frons bi-impressed; terminal labial palpi securiform; terminal maxillary palpi cylindrical, compressed laterally.
Abdomen: Six visible ventrites. Ventrites 1-5 not impressed laterally; pygidium of males moderately differentiated from that of females; females with sixth ventrite broadly rounded; pygidium simple; pygidium covered by elytra in dorsal view.
Remarks. Monophylla was described by Spinola (1841), assigning Monophylla megatoma, a species later synonymized as Monophylla terminata (Say), as the type species. Synonyms for the genus were subsequently proposed by Klug (1842) and Le-Conte (1849). Klug erected Macrotelus (1842) to designate Tillus terminatus Say as a different entity outside of species of Tillus. LeConte (1849) erected the monotypic genus Elasmocerus to synonymize Tillus (Macrotelus) terminatus Say. Both names were unnecessary replacement names for Monophylla and are now considered junior synonyms. Currently, the genus is composed of four species distributed in the United States, Mexico, Central America and Cuba. Due to a lack of material of Monophylla cinctipennis (Chevrolat 1874), this species is not covered in this study. The relatively short description given by Chevrolat (1874) is translated from French and presented here. Remaining species are redescribed here.
Sexual dimorphism is noticeable in all species comprising the genus. The form of the antennae, number of antennomeres, and differences in the shape of the pygidium will help to separate males from females (Figs 10C-D). Due to this dimorphism, keys for identification to Monophylla species are given for males and females, separately. It is advisable to determine the sex of the specimen before using the keys provided here. Sex determination can be achieved upon observation of the last antennomere. Males have the last antennomere conspicuously elongate and laterally compressed, with remaining segments remarkably reduced (Fig. 10C). Females, on the other side, have the last antennomere moderately enlarged, slightly longer than remaining antennomeres combined, and antennomeres 7-10 or 6-10 are strongly serrate (Fig. 10D). Additionally, the pygidium of males is subquadrate in shape and emarginate posteriorly (Fig. 17E-F), while females have this segment broadly rounded posteriorly ( Fig. 17G-H).

3(2)
Antennae composed of 9 antennomeres; antennomeres 3-6 reduced, conspicuously compacted and difficult to distinguish, antennomeres 7-8 serrate (Fig. 10C); pronotum uniformly brown to dark testaceous except the anterior and posterior edge with a narrow tint of testaceous to ferrugineous color (Fig. 4B)  Antennae composed of 10 antennomeres; antennomeres 3-9 compacted, moderately robust, serration on antennomeres 4-9 gradually increasing toward distal end; pronotum uniformly brown to dark testaceous except the anterior and posterior edge with a shade of testaceous to ferrugineous color (Fig. 4C)  Pronotum bicolored, outer region of pronotal disc testaceous to ferrugineous, median region of pronotal disc piceous to black (Fig. 4D)  Differential diagnosis. Monophylla californica is most similar to M. pallipes. The two species have a broad, sympatric distribution and can be misidentified. These species, however, are separated with relative ease based on the number of antennomeres. The antennae of M. californica are composed of 9 antennomeres, while the antennae of M. pallipes have 10 antennomeres.
Redescription. Male. Form: Small to moderately large, slender individuals. Color: Head, antennae, scutellum and legs testaceous to fuscus; pronotum testaceous to almost black, the anterior and posterior margins of the pronotum have a narrow to somewhat wide ferrugineous to testaceous band; thorax fuscous to almost black; elytra light testaceous to almost black, each elytron with a pale, narrow fascia on the median region of the elytral disc that initiates on the epipleural fold but does not reach the elytral suture; mouthparts fuscous, abdominal segments light testaceous to piceous (Fig. 4B).
Abdomen  Wolcott (1910), in his notes from Chevrolat's description of Macrotelus cinctipennis, mentioned the rarity of the species; he further indicated that this species was unknown to him and he had not encountered it. Redescription. Male. Form: Small to moderately large, slender individuals. Color: Head, antennae, pronotum, scutellum and legs dark testaceous to almost piceous; the anterior and posterior margins of the pronotum have a narrow ferrugineous to testaceous band; thorax ferrugineous to almost black; elytra testaceous to piceous, each elytron may have a pale to yellowish fascia on the median region of the elytral disc that initiates on the epipleural fold and does not reach the elytral suture; mouthparts fuscous, abdominal segments light testaceous to fuscous (Fig. 4C).
Redescription. Male. Form: Small to moderately large, slender individuals. Color: Head, antennae, legs and scutellum dark testaceous to almost piceous; thorax bicolored, outer region of pronotal disc testaceous to ferrugineous, median region of pronotal disc piceous to black; prosternum testaceous to ferrugineous to almost black; meso and metathorax bicolored, testaceous to ferrugineous and piceous to black; elytra fuscous to black, the anterior half of the epipleural fold testaceous to ferrugineous, some individuals with a pale to yellowish fascia on the median region of the elytral disc that initiates on the epipleural fold and does not reach the elytral suture; abdomen light testaceous to ferrugineous; mouthparts testaceous ( Fig. 4D).
Elytra: Anterior margin slightly broader than pronotum; elongate; subparallel, humeri feebly indicated, rounded; sides gradually expanding toward distal end, wider on middle third, then narrowing toward apex; elytral apices subtriangular to moderately rounded; inconspicuously dehiscent to almost confluent; elytral declivity gradual; surface clothed with fine, short, pale and dark, erect setae, intermingled with some scattered long, erect setae; conspicuously punctate, punctations wide and shallow, ir-Differential diagnosis. Species of Onychotillus somewhat resemble small-sized members of Cymatodera and species of Cymatoderella. These genera can be differentiated without difficulty based on the number of tarsal claws. Onychotillus species have a single tarsal claw, while members of Cymatodera and Cymatoderella have two tarsal claws (Fig. 7B). Additionally, the distribution of Onychotillus does not overlap with that of Cymatodera and Cymatoderella, with the former restricted to the West Indies, while the latter two have a continental distribution.
Thorax: Pronotum shiny, smooth to feebly punctate; punctation may range from narrow to slightly wide; lateral margins subparallel, slightly constricted anteriorly, somewhat wider posteriorly. Prosternum: Much wider than long, smooth to rugose, variously punctate. Mesoventrite: Wider than long, smooth, feebly to moderately punctate. Metaventrite: Convex, wider than long, surface conspicuously punctate to almost smooth. Metaventral process compressed anteriorly. Metepisterna largely exposed, the elytra do not coverer these plates in lateral view.
Elytra: Short to elongate, subparallel, widest on middle half, surface moderately to coarsely punctate; punctations arranged in regular striae; punctations do not extend to apex; epipleural fold complete, narrowing toward apex.
Remarks. Onychotillus is currently composed of five species, all inhabiting the West Indies. Of the five valid species, three are thought to be restricted to Cuba (De Zayas 1988). Based on the limited descriptive work given by De Zayas (1988), where no key for identification was provided, specimens of what appears to be Onychotillus cubana were examined (Fig. 5A); however, none of these individuals were collected in Cuba, so these specimens are tentatively assigned to O. cubana, pending further material to be examined. It is important to note that De Zayas' descriptions were based, in most cases, on a single specimen, and access to that material has been particularly difficult. Therefore, due to the lack of availability of material and the poorly detailed descriptions given by Pronotal disc piceous to almost black, with or without a metallic luster (Fig. 5B); last antennal segment about the same length as the two preceding antennomeres combined (Fig. 10F)  Pronotal disc light testaceous to ferrugineous, without a metallic luster (Fig. 5A); last antennal segment about the same length as the three to four preceding antennomeres combined (Fig. 10E)  In O. cubana the pronotal integument is light testaceous to ferrugineous (Fig. 5A), the eleventh antennomere is approximately 4× the length of the tenth antennomere (Fig. 10E), and body length ranges from 3 to 5 mm. Onychotillus vittatus, on the other side, has the pronotal integument metallic blue to almost piceous (Fig. 5B), the eleventh antennomere is about the same length as the tenth antennomere (Fig. 10F), and body length ranges from 6 to 11 mm.
Aedeagus: Not available. Sexual dimorphism: The only female examined differs from males by having the last abdominal segment broadly rounded and inconspicuously convex to almost flat, rather than subtriangular in shape and with the surface convex, as seen in males. This female also has the eleventh antennomere approximately 0.5× shorter than the same antennomere of males.      Figs 5B, 10F, 17I

Onychotillus vittatus
Type material not examined.
Type locality. Great Goat, Jamaica. Type depository: National Museum of Natural History (NMNH).
Elytra: Anterior base wider than pronotum; humeri indicated; sides subparallel; widest at middle; disc moderately convex; surface rugulose; apices rounded, slightly dehiscent; clothed with short, semirecumbent setae intermingled with some long, erect setae; sculpturing consists of coarse punctations arranged in regular striae that gradually become smaller toward apex, striae reaching elytral apex; interstices at elytral base about 2.5× the width of punctuation.
Aedeagus: Not available. Sexual dimorphism: Females of Onychotillus vittatus differ from males by having the eleventh antennomere approximately 2× longer than the tenth antennomere, rather than 3-3.5× longer, as in males. In addition, females have the lateral and posterior margins of the sixth visible ventrite broadly rounded, giving the appearance of a semicircular margin, rather than subtriangular in shape and posteriorly acuminate, as seen in males (Fig. 17I).