Fontidessus toboganensis Miller & Spangler, 2008 by original designation.

Fontidessus differs from other Bidessini by the combination of: 1) a transverse occipital line across the head absent (Figs 1–9), 2) a pair of basal pronotal striae present (Figs 1–9), 3) a basal elytral stria absent (Figs 1–9), 4) an elytral sutural stria faintly present in some specimens (e.g. Figs 4, 5), 5) the anterior clypeal margin unmodified, evenly rounded 6) the elytron without longitudinal carinae, 7) the elytral epipleuron without a transverse carina at the humeral angle, 8) the prosternal process variable in shape (Figs 10–16), but extending to metaventrite, 9) the metatrochanter extremely large relative to the metafemur, approximately 0.6 × length of metafemur (Figs 17–23), 10) overall, the habitus elongate to oval, and the lateral pronotal and elytral margins nearly continuously and shallowly curved (Figs 1–9), and 11) the lateral lobes of the aedeagus two-segmented (Figs 24–30). In addition, a new character was identified based on new material with better-preserved male genitalia. Species of Fontidessus have a distinctive ventral sclerite associated with the male median lobe. In most species, this sclerite is short and oval (Figs 26B, 28–30B), but in Fontidessus toboganensis and Fontidessus aquarupe it is elongate (Figs 25B, 27B). In Fontidessus microphthalmus, though, the median lobe is complex with large dorsal and ventral portions (Fig. 24). The dorsal part may be homologous with the dorsal sclerite of other taxa. This species is different in several respects from other Fontidessus, and it is possible the ventral portion of the median lobe is, however, not homologous with the ventral sclerite in other taxa. Fontidessus is similar to Spanglerodessus Miller & García, but that genus lacks natatory setae (a possibly derived condition based on life in hygropetric habitats where swimming is not so important) and has a body that is very robust with the lateral pronotal margins extremely broadly expanded and rounded with the lateral margin of the body distinctly discontinuous between the elytron and pronotum. Also, the male median lobe of the single species, Spanglerodessus shorti Miller & García, does not have the distinctive ventral sclerite of Fontidessus. Nevertheless, the two genera appear to be similar.

All the known species of Fontidessus are hygropetric (Figs 34–36), and most are known from only one or few localities. They are characteristic of marginal and small aquatic habitats on inselbergs or other rock surfaces (Figs 34, 36) and the margins of waterfalls (Fig. 35) in the Guaiana Shield region of northern South America (Figs 31–33). They can often be extremely abundant in these habitats. Several of the species co-occur, but others are the only known species at some sites (Figs 31–33).

Two previously described species, Fontidessus ornatus and Fontidessus wheeleri, were based on few specimens. Each of the male holotype specimens had been previously dissected, and it clearly appears, based on acquisition and examination of new material, that the male median lobes had been switched between the two and each median lobe suffered some damage during its dissection. Therefore, the incorrect male genitalia were associated with each species in the original descriptions, and the descriptions of these structures were based on somewhat damaged material (Miller and Spangler 2008). This is corrected in the following treatments.

Fontidessus Miller & Spangler, 2008

Fontidessus aquarupe Miller & Montano, sp. n.: Guyana.

Fontidessus bettae Miller & Montano, sp. n.: Venezuela.

Fontidessus christineae Miller &Montano, sp. n.: Suriname.

Fontidessus microphthalmus Miller & Montano, sp. n.: Suriname, Venezuela.

Fontidessus ornatus Miller in Miller and Spangler 2008: Guyana, Suriname, Venezuela.

Fontidessus toboganensis Miller & Spangler, 2008: Suriname, Venezuela.

Fontidessus wheeleri Miller in Miller and Spangler 2008: Venezuela.

Venezuela, Bolivar, Auyan–tepui, 5°51'N, 62°33'W.

Fontidessus microphthalmus is small (TL = 1.4–1.6 mm), but larger than all species except Fontidessus toboganensis, Fontidessus bettae, and Fontidessus aquarupe which are comparable in size (Figs 1–5). The dorsum is more pale in color than other species (darker along the elytral suture and lighter at the apex, but without distinctive maculae), and the eyes are relatively smaller than other species (Fig. 1, HW/EW = 1.4–1.5). The male genitalia are distinctive. The median lobe has two parts. The dorsal part is extremely broad, apically truncate and medially has a narrow emargination (Fig. 24A). The ventral part is elongate and apically pointed (Fig. 24A). The lateral lobes curve inward apically between the two parts of the median lobe (Fig. 24A).

Measurements. TL = 1.4–1.6 mm, GW = 0.8–0.9 mm, PW = 0.7–0.8 mm, HW = 0.5–0.6 mm, EW = 0.4 mm, TL/GW = 1.8, HW/EW = 1.4–1.5. Body (Fig. 1) broadly oval, dorsoventrally somewhat compressed; lateral outline nearly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head yellow brown, pronotum yellow, brown medially along posterior margin (Fig. 1); elytron yellow brown, apically lighter yellow brown. Ventral surfaces of thorax and abdomen brown except prosternum, prosternal process, propleuron and pronotal epipleuron yellow-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with distinct microreticulation; eyes small (Fig. 1, HW/EW = 1.4–1.5). Pronotal surface similar to that of head; with posterior angles obtuse; lateral bead narrow, of even width throughout, lateral margins weakly curved; pronotal striae finely incised, extending about 1/3 distance across pronotum (Fig. 1). Elytron with anterolateral angle obtuse, not extended anteriorly (Fig. 1); surface similar to pronotum, covered with fine microreticulation. Prosternal process narrow, lateral margins evenly curved and posteriorly convergent, apex of process narrowly rounded (Fig. 10); metacoxal process with lateral lobe minute. Pro- and mesotarsi relatively narrow in both male and female, but broader in male. Metatrochanter extremely large relative to metafemur (Fig. 17).

Male genitalia. Median lobe complex with two sections 1) an elongate ventral structure that is broad and evenly convergent to a narrowly rounded apex in dorsal aspect (Fig. 24A) and slender and evenly convergent to slight curved apex in lateral aspect (Fig. 24B), and 2) an elongate dorsal structure that is very broad, apically broadly truncate and medially narrowly emarginate in dorsal aspect (Fig. 24A) and slender in lateral aspect (Fig. 24B). Lateral lobes elongate, slender with apical segment medially curved between ventral and dorsal portions of median lobe (Fig. 24A).

No significant variation was observed among the few specimens examined.

Etymology. The name of this species is derived from the Greek micro- meaning “small” and ophthalmos meaning “eye” for the relatively small eyes present in this species.

The species is known from two sites, one on the Auyan Tepui of the Gran Sabana of Venezuela, and the other on Kasikasima in the Sipilawini District of Suriname (Fig. 31) suggesting that the species may be characteristic of the Guyana Highlands. The specimens from Suriname are clearly hygropetric (Fig. 34), but the habitat is not known for the Venezuela specimens which were collected in an “intercept trap”.

This is a problematic species. It is, in many ways, like other species of Fontidessus, but the male median lobe is unusually modified and the “ventral sclerite” is either absent or the large ventral part (Fig. 24) is homologous with that structure in the other species. Also, the eyes are quite small (Fig. 1). In some ways, it approaches Spanglerodessus shorti Miller and García in being broad, but its shape and structure, with the median lobe divided into two portions and the dorsal portion apically emarginate, is much more like species of Fontidessus.

Holotype in MIZA: ♂ labeled, “VENEZUELA. Bolivar Auyan–tepui 1700m 5°51'N, 62°33'W 7–14–94 J.L.Garcia–A.Chacón/ Trampa interceptacion [“intercept trap”]/ HOLOTYPE: Fontidessus microphthalmus Miller & Montano, 2014 [red label with black line border]”. Paratypes: 4 labeled same as holotype except “…PARATYPE: Fontidessus microphthalmus Miller & Montano, 2014 [blue label with black line border]”; 9 labeled “SURINAME: Sipaliwini District 2°58.555'N, 55°24.739'W 515 m Camp 4 (summit), Kasikasima leg. A. Short; small seepage on top of METS trail; 24.iii.2012 2012 CI–RAP Survey SR12–0324–01A/ PARATYPE: Fontidessus microphthalmus Miller & Montano, 2014 [blue label with black line border]”.

Guyana, Region IX, Kusad Mts, Mokoro Creek, 2°48.531'N, 59°51.900'W.

Fontidessus aquarupe is small (TL = 1.5–1.7 mm), but larger than all Fontidessus species except Fontidessus toboganensis and Fontidessus bettae, which are comparable in size (Figs 1–5). The dorsum is dark with diffuse yellow maculae on the pronotum and elytron. The male genitalia are distinctive. The median lobe is broad and apically broadly pointed and curved dorsad (Fig. 24A, C). The ventral sclerite is long and broad, and apically subtruncate with distinct lateral pointed lobes (Fig. 24B). The lateral lobes are basally broad and apically are elongate and slender (Fig. 25A, D). The prosternal process is relatively broad, flattened and apically narrowly rounded (Fig. 11).

Measurements. TL = 1.5–1.7 mm, GW = 0.9–1.0 mm, PW = 0.8–0.9 mm, HW = 0.5–0.6 mm, EW = 0.3-0.4 mm, TL/GW = 1.7, HW/EW = 1.5–1.6. Body (Fig. 2) oval, robust, dorsoventrally somewhat compressed; lateral outline nearly continuous between pronotum and elytron; lateral margins of pronotum evenly curved; lateral margins of elytron evenly and broadly curved.

Coloration. Head dark brown; pronotum dark brown, black along anterior and posterior margins, with yellow transverse macula on each side anterior to middle (Fig. 2); elytron brown with diffuse pale areas anteriorly and with posterior extensions along lateral margins and near suture, apex with triangular pale area (Fig. 2). Ventral surfaces black to dark red-brown except prothorax, including prosternal process, yellow; antennae and appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with distinct microreticulation comprised of minute, isodiametric cells; eyes medium in size (Fig. 2, HW/EW = 1.5–1.6). Pronotal surface similar to head; with posterior angles obtuse; lateral bead narrow, of even width throughout, lateral margins weakly curved; pronotal striae fine, extending nearly 1/2 distance across pronotum (Fig. 2). Elytron with anterolateral angle obtuse, not extended anteriorly (Fig. 2); surface similar to pronotum, covered with fine microreticulation. Prosternal process moderately narrow, flattened, lateral margins posteriorly convergent, apex of process narrowly rounded (Fig. 11); metacoxal process with lateral lobe minute. Pro- and mesotarsi relatively narrow in both male and female, but slightly broader in male. Metatrochanter extremely large relative to metafemur (Fig. 18).

Male genitalia. Median lobe in dorsal aspect elongate, broad, apically abruptly constricted, terminating in two elongate, narrow rami with medial deep, narrow emargination, apex with inconspicuous, diaphanous lobes laterally (Fig. 25A); in lateral aspect slender, elongate, conspicuously recurved with apical portion very slender and apically narrowly pointed (Fig. 25C); with elongate ventral sclerite that is broad and apically truncate, terminating in pointed lobes laterally (Fig. 25B). Lateral lobes elongate, apically abruptly sinuate, basally broad (Fig. 25D).

Specimens vary in the extent of dorsal coloration, particularly the extent to which the anterior diffuse elytral macula extends posteriorly along the lateral and sutural margins.

This species is named aquarupe from the Latin, aqua, meaning “water”, and rupe, meaning “rock” or “cliff” since specimens are known from hygropetric habitats.

Fontidessus aquarupe is known only from seepages and wet rocks near a single site in the Kusad Mountains of southwestern Guaya (Fig. 32).

Holotype in CSBD: male labeled, “GUYANA: Regions IX 2°48.531'N, 59°51.900'W, 170m Kusad Mts., large seepage nr. Basecamp: on wet rocks leg. A. Short & W. Washington GY13-1024-03C/ SEMC1047996 KUNHM-ENT [barcode label]/ HOLOTYPE: Fontidessus aquarupe Miller & Montano, 2014 [red label with black line border]”. Paratypes: 69 labeled same as holotype except “…/PARATYPE: Fontidessus aquarupe Miller & Montano, 2014 [blue label with black line border]”; 69 labeled, “GUYANA: Region IX 2°48.531'N, 59°51.900'W 170m Kusad Mts., Mokoro Creek main seepage area leg. Short, Isaacs, Salisbury 27.x.2013; GY13-1027-03B /PARATYPE: Fontidessus aquarupe Miller & Montano, 2014 [blue label with black line border]”.

Venezuela, Bolivar State, Gran Sabana, E Pauji, Salto Catedral, 4°31'19.1"N, 61°31'34.0"W.

Fontidessus bettae is small (TL = 1.4 mm), but larger than all species except Fontidessus toboganensis, Fontidessus aquarupe, and Fontidessus microphthalmus, which are comparable in size (Figs 1–5). The dorsal maculae are distinctive. The elytron has a transverse, well-demarcated yellow macula near the anterior margin and a smaller, subapical yellow macula (Fig. 3). The anterior macula does not have medial or lateral posterior extensions along the disc (Fig. 3) as is often the case in Fontidessus tambopaticus (Fig. 5). The eyes in Fontidessus bettae are larger (Fig. 3, HW/EW = 1.5–1.6) than in Fontidessus microphthalmus (Fig. 1, HW/EW = 1.4–1.5). The male median lobe terminates in a narrow, pointed apex with only small lateral hyaline lobes (Fig. 26).

Measurements. TL = 1.4–1.5 mm, GW = 0.9 mm, PW = 0.7 mm, HW = 0.4–0.5 mm, EW = 0.3 mm, TL/GW = 1.7–1.8, HW/EW = 1.5–1.6. Body (Fig. 3) broadly oval; lateral outline nearly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head brown, pronotum dark brown along anterior and posterior margins with prominent yellow transverse region near anterior margin, darker yellow brown medially (Fig. 3); elytron brown with distinct, well-defined, yellow, transverse but slightly oblique macula near base and yellow triangular shaped macula near apex (Fig. 3). Ventral surfaces of thorax and abdomen dark brown to black except prosternum, prosternal process, propleuron and pronotal epipleuron yellow-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with distinct microsculpture in the form of small cells; eyes medium in size (Fig. 3, HW/EW = 1.5–1.6). Pronotal surface similar to that of head; with posterior angles obtuse; lateral bead narrow, of even width throughout; pronotal striae finely incised, extending nearly 1/2 distance across pronotum (Fig. 3). Elytron with anterolateral angle obtuse, not extended anteriorly (Fig. 3); surface similar to pronotum. Prosternal process moderately broad, lateral margins evenly curved, apex of process narrowly rounded (Fig. 12); metacoxae impunctate, but with distinct microreticulation; metacoxal process with lateral lobe minute. Pro- and mesotarsi relatively narrow in both male and female, but slightly broader in male. Metatrochanter very large in relation to metafemur (Fig. 19).

Male genitalia. Median lobe in dorsal aspect broad basally, with lateral margins approximately evenly tapered to extremely slender, bifid apex, with small, but distinctive, hyaline lobes laterally (Fig. 26A); in lateral aspect moderately broad basally, apical portion moderately straight, lateral margins evenly tapered to extremely slender apex (Fig. 26C); with broad, rounded dorsal sclerite (Fig. 26B). Lateral lobe in lateral aspect broad basally, apical segment slender and moderately straight (Figs 26D).

There is some minor variation in the extent and distinctiveness of the dorsal maculae, but relatively little variation among the few specimens examined.

This species is named to honor the second author’s grandmother, Elizabeth (Betty) Baca, who deeply inspired her to live well and seek knowledge.

Fontidessus bettae is known only from the type series in the Gran Sabana of Venezuela (Fig. 31). It was collected from “waterfall seeps”, a hygropetric habitat along the margin of a waterfall (Fig. 35).

Holotype in MIZA: male labeled, “VENEZUELA: Bolivar State 4°31'19.1"N, 61°31'34.0"W, 860 m Gran Sabana, E Pauji. Salto Catedral 16.vii.2010 leg. Short & Tellez waterfall seeps; VZ10–0716–03B/ HOLOTYPE: Fontidessus bettae Miller & Montano, 2014 [red label with black line border]”. Paratypes: 19 labeled same as holotype except “…/PARATYPE: Fontidessus bettae Miller & Montano, 2014 [blue label with black line border]”.

Venezuela, Territorio Federal Amazonas, 40km S Puerto Ayacucho, at El Tobogan, Coromoto.

Although small for diving beetles, this species is relatively large for the genus (Figs 4, 5, TL = 1.5–1.6 mm). The prosternal process is moderately broad and parallel-sided and has the apex broadly truncate (Fig. 13). The male genitalia are distinctive with the median lobe elongate, slender and broadly recurved in lateral aspect (Fig. 27C). There is an elongate ventral sclerite that fits into the ventral groove of the median lobe (Figs 27B, C). Specimens are variable in coloration with specimens from Suriname indistinctly marked with maculae (Fig. 4) and specimens from Venezuela marked with diffuse but distinctive maculae on the elytra (Fig. 5).

Measurements. TL = 1.5–1.6 mm, GW = 0.8–0.9 mm, PW = 0.6–0.7 mm, HW = 0.4–0.5 mm, EW = 0.3–0.4 mm, TL/GW = 1.8–1.7, HW/EW = 1.6–1.7. Body (Figs 4, 5) oval, elongate; lateral outline nearly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head yellow brown, pronotum yellow brown, brown medially along posterior margin; elytron brown with the following yellow maculae: 1) a basal macula in a band extending from lateral to sutural margins, posterior margin of macula irregular, often with medial extension posteriorly along elytral suture, 2) a lateral longitudinal macula at humeral angle, 3) a narrow longitudinal macula along lateral margin medially, and 4) a subtriangular subapical macula (Figs 4, 5). Many specimens with elytral maculae reduced or indistinct (Fig. 4). Ventral surfaces of thorax and abdomen brown except prosternum, prosternal process, propleuron and pronotal epipleuron yellow-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with indistinct microsculpture in the form of small cells; eyes medium in size (Figs 4, 5, HW/EW = 1.6–1.7). Pronotal surface similar to that of head; with posterior angles obtuse; lateral bead narrow, of even width throughout; pronotal striae finely incised, extending nearly 1/2 distance across pronotum (Figs 4, 5). Elytron with anterolateral angle obtuse, not extended anteriorly (Figs 4, 5); surface similar to pronotum. Prosternal process broad, lateral margins subparallel, apex of process broadly rounded (Fig. 13); metacoxal process with lateral lobe minute. Pro- and mesotarsi relatively narrow in both male and female, but slightly broader in male. Metatrochanter very large relative to metafemur (Fig. 20).

Male genitalia. Median lobe in dorsal aspect elongate, slender, apically terminating in two elongate, narrow rami with medial deep, narrow emargination, long apicies distinctly expanded laterally (Fig. 27A); in lateral aspect slender, elongate, conspicuously recurved with apical portion very slender and apically narrowly pointed (Fig. 27C); with elongate ventral sclerite that is pointed apically (Fig. 27B). Lateral lobes elongate, apically slightly curved and narrowly rounded (Fig. 27D).

Female genitalia. Bursa copulatrix elongate and narrow; spermathecal duct long, slender, somewhat coiled, expanded before receptacle; receptacle small, about half size of spermatheca, intermediate duct between receptacle and spermatheca broad; spermatheca globular, spermathecal spine prominent, but not elongate; fertilization duct elongate, tightly curved in spiral, attaching to large fertilization sac; vagina elongate, moderately narrow; gonocoxae elongate, slender with abrupt, small, triangular expansion at apex.

This species exhibits considerable variability in the extent of yellow coloration on the dorsal surface. Specimens from Venezuela are usually heavily marked with yellow maculae and fasciae on the elytron and have the pronotum and head yellow (Fig. 5). Specimens from Suriname, in contrast, have the elytral maculae reduced and very indistinct and the head and pronotum darker (Fig. 4).

Fontidessus toboganensis is known from the extreme western margin of the Guayana Shield in the area around Puerto Ayacucho, Venezuela and from a few localities in Suriname (Fig. 32). In both areas it is extremely common and abundant in hygropetric habitats. The broadly disjunct distribution and differences in coloration suggest the possibility that the two populations are different species, but the male genitalia are shaped the same and the body is similarly shaped and sized. This is similar to Fontidessus ornatus which is also darker and less maculate in eastern localities than in western ones, though that species is also known from localities in between.

~627 specimens from the following localities: VENEZUELA: Amazonas: 40km S Puerto Ayacucho, El Tobogan, Caño Coromoto 5.38678°N, 67.61537°W; nr Iboruwa: Tobogancito, 5.8069°N, 67.43855°W; Bolivar: Los Pijiguaos at rock outcrop, 6.59361°N, 66.82063°W. SURINAME: Sipaliwini District, Raleighfallen Nature Reserve plateau below Voltzberg, seepage, 4.68276°N, 56.1877°W. Sipaliwini District, Tafelberg Summit, nr Augustus Creek Camp, large seepage area, 3°55.600'N, 56°11.300'W 600m; Sipaliwini District, Tafelberg Summit, near Caiman Creek Camp, washing seepage, 3°53.942'N, 56°10.849'W, 733m.

Suriname, Sipaliwini District, Kasikasima, small seepage on top of METS trail, 2°58.555'N, 56°24.739'W, 515m.

Fontidessus christineae is extremely small (<1.2 mm) and very dark testaceous dorsally with only some diffuse, transverse yellow margins on the pronotum (Fig. 6). The male median lobe terminates apically in two broadly lobate rami (Fig. 28).

Measurements. TL = 1.1–1.2 mm, GW = 0.7 mm, PW = 0.6 mm, HW = 0.4 mm, EW = 0.3 mm, TL/GW = 1.7, HW/EW = 1.5–1.6. Body (Fig. 6) broadly oval; lateral outline nearly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head dark red-brown, lighter anteriorly, pronotum dark red-brown along anterior and posterior margins with indistinct yellow-red transverse region across anterior half, darker yellow brown medially (Fig. 6); elytron dark red-brown (Fig. 6). Ventral surfaces of thorax and abdomen dark brown to dark red-brown except prosternum, prosternal process, propleuron and pronotal epipleuron red-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with distinct microsculpture in the form of small cells; eyes medium in size (Fig. 6, HW/EW = 1.5–1.6). Pronotal surface similar to that of head; with posterior angles obtuse; lateral bead narrow, of even width throughout; pronotal striae finely incised, extending nearly 1/2 distance across pronotum (Fig. 6). Elytron with anterolateral angle obtuse, not extended anteriorly (Fig. 6); surface similar to pronotum but with fine microsculpture cells more distinct. Prosternal process moderately broad, lateral margins slightly angulate, apex of process narrowly rounded (Fig. 14); metacoxae impunctate, but with distinct microreticulation; metacoxal process with lateral lobe minute. Pro- and mesotarsi broader in male than female. Metatrochanter very large relative to metafemur (Fig. 21).

Male genitalia. Median lobe in dorsal aspect deeply emarginate medially, each arm moderately slender, lateral margin sinuate, medial margin evenly curved, apex expanded and directed medially, with large, hyaline, rounded lobes laterally (Fig. 28A); in lateral aspect very broad, medially curved ventrad, apex tapered to sub-truncate apex (Fig. 28C); with broad, rounded dorsal sclerite (Fig. 28B). Lateral lobe in lateral aspect with basal segment broad, dorsally acute along margin, apical segment slender, apically slightly expanded to narrowly rounded apex, with fine setae along ventral margin (Figs 28D).

No significant variation was identified in the single series of this species.

This species is named after the second author’s mother, Christine Anne Montano, who taught her to work hard and seek to achieve.

Fontidessus christineae is known only from one area, on Mount Kasikasima in Suriname (Fig. 32) in a “small seepage” and in the “main seepage area” (Fig. 36). The localities are at 400 and 515 meters

Holotype in NZCS male labeled, “SURINAME: Sipaliwini District 2°58.555'N, 56°24.739'W, 515 m Camp 4 (summit), Kasikasima leg. A. Short; small seepage on top of METS trail; 24.iii.2012 2012 CI–RAP Survey SR12–0324–01A/ SEMC1087097 KUNHM–ENT [barcode label]/ HOLOTYPE Fontidessus christineae Miller, 2013 [red label with black line border]”. Paratypes 7, 6 labeled same as holotype except with KUNHM–ENT numbers SEMC1087380, SEMC1087091, SEMC1087089, SEMC1087088, SEMC1087096, SEMC1087098. One paratype labeled “SURINAME: Sipaliwini District 2°58.613'N, 55°24.683'W, 400 m Camp 4 (high), Kasikasima leg. A. Short; main seepage area 24.iii.2012; SR12–0324–01C 2012 CI–RAP Survey/ SEMC1088139 KUNHM–ENT”. Paratypes also with “…/PARATYPE Fontidessus christineae Miller, 2013 [blue label with black line border]”.

Venezuela, Territorio Federal Amazonas, 40km S Puerto Ayacucho, at El Tobogan, Coromoto.

Fontidessus ornatus are very small (Figs 7, 8, TL = 1.09–1.20). Specimens are diffusely marked with yellow on the elytron anteriorly, medially and laterally (Fig. 8) or are nearly entirely darkly colored (Fig. 7). The median lobe terminates apically in two slender rami with two very broad, lateral hyaline lobes (Fig. 29).

Measurements. TL = 1.1–1.2 mm, GW = 0.6–0.7 mm, PW = 0.6–0.7 mm, HW = 0.4–0.5 mm, EW = 0.1–0.2 mm, TL/GW = 1.8–1.9, HW/EW = 1.5–1.6. Body (Figs 7, 8) oval, elongate; lateral outline slightly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head yellow brown, darker in region near medial margins of eyes; pronotum yellow brown, diffusely brown medially along posterior margin and in narrow band along anterior margin; elytron brown with diffuse yellow pattern, yellow basally, laterally along about ¾ length of elytra and in subtriangular subapical area (Fig. 8). Other specimens much darker, with elytral maculae reduced overall (Fig. 7). Ventral surfaces of thorax and abdomen brown except prosternum, prosternal process, propleuron and pronotal epipleuron yellow-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny with indistinct microsculpture in the form of small cells; eyes medium in size (Figs 7, 8, HW/EW = 1.5–1.6). Pronotal surface similar to that of head; with posterior angles obtuse; lateral bead slender, of even width throughout; pronotal striae finely incised, extending nearly 1/2 distance across pronotum (Figs 7, 8). Elytron with anterolateral angle obtuse, not extended anteriorly (Figs 7, 8); surface similar to pronotum but with microsculpture more indistinct. Prosternal process relatively narrow, lateral margins tapered to narrowly rounded apex (Fig. 15); metacoxal process with lateral lobe minute. Pro- and mesotarsi relatively narrow in both male and female. Metatrochanter very large relative to metafemur (Fig. 22).

Male genitalia. Median lobe in dorsal aspect complex, apically terminating in two elongate, narrow rami with medial deep, narrow emargination, laterally with broad, hyaline lobes (Fig. 29A); in lateral aspect narrow, straight, apically with distinct subapical hyaline lobe and apex slightly bent, apically very slender (Fig. 29C); ventral sclerite short, broad, apically rounded (Fig. 29B). Lateral lobe slender medially, apically expanded and broadly rounded (Fig. 29D).

This species exhibits considerable variation in color between the two main regions in which it has been collected (Surinam/Guyana and Venezuela). The eastern specimens are noticeably darker in overall coloration (Fig. 7) than those from Venezuela which are more distinctly marked with yellow maculae on the elytra and lighter in color on the pronotum and head (Fig. 8). The distinctive male genitalia (Fig. 29) are similar in each of the two populations, though, and so this color variation is regarded as intraspecific.

Fontidessus ornatus is more widespread and common than other species in the genus. It ranges from the western margin of the Guiana Shield through northeastern Venezuela to central and southern Suriname (Fig. 33). It is found in hygropetric habitats.

The original description of Fontidessus ornatus included 15 specimens. This type series was mixed together with specimens of Fontidessus toboganensis and Fontidessus wheeleri. The holotype of Fontidessus ornatus had already been dissected, but based on considerable new material, it appears that the genitalia had been damaged somewhat and, worse yet, exchanged with the genitalia of what became the holotype of Fontidessus wheeleri. The genitalia are redescribed and reillustrated here based on newly dissected specimens with greater precision and in correct association with the species to which they belong.

~400 total from the following localities: VENEZUELA: Amazonas: 40km S Puerto Ayacucho, El Tobogan, Caño Coromoto 5.38678°N, 67.61537°W; Bolivar: Los Pijiguaos at rock outcrop, 6.59361°N, 66.82063°W; rock outcrop by Rio Cuchivero 7.45835°N, 65.86821°W; outcrop ca 15km NE Pijiguaos, 6.96506°N, 66.60653°W; rock outcrop by morichal, 6.86993°N, 66.59083°W; 2km E Rio Chucivero, 7.45835°N, 65.86821°W; ca 25km E El Burro, 6.21794°N, 67.24066°W; along La Escalera, Hwy 10, 6.08186°N, 61.39797°W; ca 14km E Rio Aro, 7.23988°N, 64.0322°W. SURINAME: Sipaliwini District: camp 2, Sipaliwini Riv., 2.18288°N, 56.78725°W; Raleighfallen Nature Reserve plateau below Voltzberg, 4.68276°N, 56.1877°W; Sipaliwini District: Tafelberg Summit, nr Augustus Creek Camp, large seepage area, 3°55.600'N, 56°11.300'W 600m. GUYANA: Region IX, Kusad Mtns, large seepage nr. Basecamp; on wet rocks, and Mokoro Creek main seepage area, 2°48.531'N, 59°51.900'W, 170m.

Venezuela, Territorio Federal Amazonas, 40km S Puerto Ayacucho, at El Tobogan, Coromoto.

Fontidessus wheeleri are small (Fig. 9, TL = 1.2–1.3 mm). Specimens are marked on the elytra with transverse and longitudinal yellow maculae that are distinctly demarcated. The male median lobe terminates in two, short, slender rami with small, subapical, lateral, hyaline lobes (Fig. 30).

Measurements. TL = 1.2–1.3 mm, GW = 0.6–0.7 mm, PW = 0.5–0.6 mm, HW = 0.4–0.5 mm, EW = 0.2–0.3 mm, TL/GW = 1.7–1.8, HW/EW = 1.6–1.7. Body (Fig. 9) oval, elongate; lateral outline slightly continuous between pronotum and elytron; lateral margins of pronotum gently curved; lateral margins of elytron evenly and gently curved.

Coloration. Head yellow brown, brown along posterior margins and medial margins of eyes; pronotum broadly brown along posterior margin, narrowly dark brown along anterior margin; elytron brown with the following yellow maculae: 1) a basal macula in an irregular band extending posteriorly along suture at medial margin, 2) a lateral longitudinal macula posterior to humeral angle, broader anteriorly and extending posteriorly in narrow band to near apex, 3) a subtriangular subapical macula (Fig. 9). Ventral surfaces of thorax and abdomen dark brown except prosternum, prosternal process, propleuron and pronotal epipleuron yellow-brown; appendages yellow to yellow-brown.

Sculpture and structure. Head with very fine, inconspicuous, irregular punctation, surface between punctures shiny, without distinct microsculpture; eyes medium in size (Fig. 9, HW/EW = 1.6–1.7). Pronotal surface similar to that of head, with posterior surface with fine microsculpture; with posterior angles obtuse; lateral bead slender, of even width throughout; pronotal striae finely incised, extending nearly 1/2 distance across pronotum (Fig. 9). Elytron with anterolateral angle obtuse, not extended anteriorly (Fig. 9); surface similar to pronotum, with microsculpture indistinct. Prosternal process elongate and slender, lateral margins slightly concave, apex of process rounded (Fig. 16); metacoxal process with lateral lobe small. Pro- and mesotarsi relatively narrow in both male and female, but slightly broader in male. Metatrochanter very large relative to metafemur (Fig. 23).

Male genitalia. Median lobe in ventral aspect broad, tapering slightly, apically bifid and slender, deeply and narrowly emarginate medially, with short, hyaline, sub-triangular lobes subapically on each side (Fig. 30A); in lateral aspect moderately broad, curved, with apical portion evenly tapered to pointed apex (Fig. 30C). Lateral lobe elongate, expanded apically, broadly rounded at apex, with series of long setae along dorsal margin (Fig. 30B).

The extent of the dorsal maculae varies among specimens with some having the maculae reduced, but most with extensive maculae that are well-defined.

This species is known only from a few localities along the far western margin of the Guiana Shield around Puerto Ayacucho (Fig. 31). Specimens have been found in hygropetric situations.

This species was originally based on two specimens (the holotype and a paratype) that were originally collected together with the type series of Fontidessus ornatus and Fontidessus toboganensis, which were described at the same time (Miller and Spangler 2008). The holotype of Fontidessus wheeleri had been dissected some time prior to the original description, but, based on a few additional specimens examined for this paper, the male genitalia were apparently somewhat damaged (torn and crushed somewhat), and also switched with those of the holotype of Fontidessus ornatus, which had also been dissected previously. For that reason, the male genitalia are redescribed and reillustrated here based on newly dissected specimens in association with the correct species based on examination on a few additional specimens. This species has been only rarely collected.

Six total specimens from the following localities: VENEZUELA: Amazonas: 40km S Puerto Ayacucho, El Tobogan, Caño Coromoto 5.38678°N, 67.61537°W; ca 15km S Puerto Ayacucho, 5.51038°N, 67.60181°W; Bolivar: ca 25km E El Burro, 6.21794°N, 67.24066°W.