Mecoloesthus, SIMON, 1893

HUBER, BERNHARD A., 2000, New World Pholcid Spiders (Araneae: Pholcidae): A Revision At Generic Level, Bulletin of the American Museum of Natural History 2000 (254), pp. 1-348 : 255-271

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https://doi.org/ 10.1206/0003-0090(2000)254<0001:NWPSAP>2.0.CO;2

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https://treatment.plazi.org/id/03ACD276-8FAA-FEE7-FF15-FD1241863BEC

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scientific name

Mecoloesthus
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MECOLOESTHUS SIMON, 1893

Mecoloesthus Simon, 1893b: 482 (type species by original designation M. longissimus Simon, 1893 ; examined). – Bonnet, 1957: 2742 (justification of preference of Mecoloesthus over Mecolaesthus ).

DIAGNOSIS: Medium-sized to large (total length ~ 2–7 mm), eight-eyed pholcids; distinguished from other New World genera by the posteriorly inflated prosoma.

DESCRIPTION: Total length usually ~ 2–4 mm, only M. longissimus , with its long opisthosoma, up to 7 mm. Carapace with thoracic groove, which disappears posteriorly because of inflation of carapace (e.g., figs. 1025–1026); ocular area moderately elevat- ed; eight eyes; AME smallest. Distance PME-ALE usually large (~ 80–90% of PME diameter; smaller in some species assigned tentatively: M. yawaperi , n. sp.; hoti , n. sp.; arima , n. sp.). Male clypeus unmodified. Male chelicerae with one or more pairs of variously shaped apophyses, without stridulatory ridges. Male palps relatively small in relation to overall size; coxa with retrolateral apophysis, femur with retrolateral apophysis proximally, with variably shaped ventral apophysis distally, procursus and bulb variable. Tarsal organ exposed (examined: M. longissimus : fig. 79). Legs of varying length (leg 1 usually 6–12 × body length; tibia 1 l/ d: 35–114); leg 1 always longest, legs 2 and 4 about same length, leg 3 shortest; without spines, without curved and vertical hairs (two species assigned tentatively have many vertical hairs on metatarsi: M. yawaperi , hoti ); retrolateral trichobothrium of tibia 1 very proximal (1.5–6%); tarsus with ~ 25 to> 35 pseudosegments. Opisthosoma longer than high, pointed at spinnerets, in type species unusually long. Male gonopore without spigots (examined: M. longissimus : fig. 136). ALS with only one piriform gland spigot each (examined: M. longissimus : fig. 180), other spinnerets typical for family.

Sexual dimorphism slight (females of most species unknown); in M. longissimus females with opisthosoma shorter than in males.

MONOPHYLY: The species included share the posteriorly inflated prosoma. In some species, including the type species, this inflation is very slight, but in other close relatives the inflation is very distinct (e.g., M. mucuy , n. sp.: figs. 1024–1026; azulita , n. sp.; peckorum , n. sp.).

GENERIC RELATIONSHIPS: Two characters vaguely hint to a closer relationship with Coryssocnemis : the blunt apophysis close to the lamina on the male chelicera (present only in M. longissimus ), which might be a homolog to the upward-bent apophysis in Coryssocnemis ( C. monagas has the same blunt apophysis instead of the ‘‘typical’’ upward-bent apophysis: fig. 1001); and the distal apophysis on the male palpal femur. (This character may also unite Mecoloesthus with further mainly Venezuelan genera: Systenita , Kaliana ).

SPECIFIC RELATIONSHIPS: A number of species (core-group) seem close to M. longissimus (similar procursi and bulbs), but have shorter opisthosomata and shorter legs: M. mucuy , azulita , peckorum , tabay , n. sp., cornutus , n. sp. All other species are assigned tentatively: (1) three closely related species from the Antilles: M. lemniscatus (Simon, 1894) , n. comb., and M. nigrifrons (Simon, 1894) , n. comb. (both transferred from Psilochorus ), and the newly described M. taino , n. sp.; these form a monophyletic group, sharing details of the procursus, especially a unique internal ‘‘reservoir’’ (arrow in fig. 1085); (2) four newly described long-legged species that show substantial variation in genital structure, but share the inflated carapace: M. yawaperi , putumayo, arima , hoti .

DISTRIBUTION: The core-group is so far restricted to northern Venezuela. Together with the species assigned tentatively, the genus has a wide distribution in northern South America, from southern Colombia and Manaus in Brazil to the Lesser Antilles.

COMPOSITION: The genus as construed here includes 13 named species: the type species M. longissimus (which is redescribed below), and 12 further species, 10 of which are newly described below. The two species not treated herein ( M. lemniscatus , nigrifrons ) were recently redescribed (Huber, 1997b).

Mecoloesthus longissimus Simon, 1893 Figures 79 View Figs , 136 View Figs , 180 View Figs , 1014–1023

Mecoloesthus longissimus Simon, 1893a: 320– 321 ; 1983b: 479–482, figs. 439, 443, 469.—

Caporiacco, 1955: 299. – Huber, 1997b: 588– 591, figs. 12a–e, 13a–d.

TYPES: Male lectotype, 133 3♀ paralectotypes from Tovar (Aragua), and Corosal (Distrito Federal), Venezuela ; Jan.-Feb. 1888 (E. Simon), in MNHN (11024), examined (see Huber, 1997b for redescription of this material) .

NOTE: Simon’s type material contains one slightly deviating male, probably because Simon lumped the material from two different localities (Tovar and Corosal). Discussing these differences, I have previously (Huber, 1997b) not made a decision on the taxonomic status of the ‘‘aberrant’’ male. With the additional material studied herein I tend to see one quite variable species rather than several minimally different ones, primarily because the male palp is almost indistinguishable, even comparing the size of bulb and procursus in individuals of very different body size. (Note that the differences in shape between the drawings of the palp in Huber, 1997b, and those herein result mostly from slightly different angles of view.) Apart from total size, variation mainly occurs in the male chelicerae (see Variation below). The redescription herein deals with populations of rather small individuals, and gives some new data on ultrastructure and variation.

DIAGNOSIS: Distinguished from congeners by the long opisthosoma (especially in the male), and the shape of the procursus (figs. 1019–1020).

MALE (Guatopo Nat. Park): Total length 3.0, carapace width 0.81; leg 1: 32.7 (8.0+0.4+7.7+14.7+1.9), tibia 2 missing, tibia 3: 3.7, tibia 4: 4.1; tibia 1 l/d: 114. Habitus as in fig. 1014; distance PME-ALE about 80% of PME diameter. Carapace ochre to light brown, with dark Y mark; clypeus light brown, sternum ochre-yellow. Chelicerae light brown, with two pairs of frontal apophyses and pair of sclerotized patches (fig. 1018). Palps as in figs. 1015–1017, femur with conspicuous apophyses (fig. 1016), procursus simple (figs. 1019–1020), with prolateral apophysis subdistally (fig. 1020), bulb as in fig. 1021. Tarsal organ exposed (fig. 79). Legs light brown, femora and tibiae with light distal tips, without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 at 3%; tarsus 1 with ~ 30 pseudosegments. Opisthosoma light greenish, with darker greenish spots dorsally, light brown genital plate, black spot between genital plate and spinnerets; gonopore without epiandrous spigots (fig. 136); ALS with only one piriform gland spigot each (fig. 180).

FEMALE (Guatopo Nat. Park): Total length 2.3; carapace width 0.87; tibia 1 missing, tibia 2: 3.1, tibia 3: 2.3, tibia 4: 2.8. Very similar to male, but anterior part of opisthosoma not so elongated. Epigynum small, very simple, consisting of pair of brown plates between which semispherical pore plates were visible in one individual (fig. 1022). Dorsal view as in fig. 1023.

VARIATION: Tibia 1 in 2 other males from Guatopo Nat. Park: 9.1, 10.4; in one male the ventral black mark on the opisthosoma was a long band rather than a spot. Total length varied as follows (resulting mainly from variation in opisthosoma length): Simon’s type material: 4.5–7.0; male from Rancho Grande (see below): 5.7; male from ‘‘Golfo Triste’’ (see below): 3.9; males from Guatopo Nat. Park: 3.0–4.0. The proximal pair of apophyses on the chelicerae is absent in some males (fig. 12E in Huber, 1997b).

DISTRIBUTION: Known from several localities in northern Venezuela (Aragua, Distrito Federal, Miranda, Carabobo).

MATERIAL EXAMINED: VENEZUELA: Aragua and Distrito Federal: types above ; Aragua: Rancho Grande near Maracay, Mar. 15–31, 1946 (W. Beebe ‘‘et al.’’), 13 in AMNH. Carabobo: Golfo Triste (10°40'N, 68°10'W), Sept. 6, 1942 (W. Beebe ‘‘et al.’’), 13 2♀ 1 juvenile in AMNH. Miranda: Guatopo Nat. Park , 35 km N Altagracia, Agua Blanca, 400 m elev., May 31–June 7, 1987 (S. & J. Peck), ‘‘ravine FITs,’’ 53 1♀ in AMNH GoogleMaps ; same locality and collectors, June 7–14, 1987, forest streamside, 23 in AMNH GoogleMaps ; same locality and collectors, June 3–10, 1987, forest floor sweeping, 1♀ in AMNH GoogleMaps ; Guatopo Nat. Park , El Lucero, 700 m elev., May 31–June 7, 1987 (S. & J. Peck), ‘‘ravine FIT,’’ 23 in AMNH ; Guatopo Nat. Park, Santa Cruzita , 450 m elev., Feb. 14, 1984 (J. Coddington), 33 2♀ in USNM ; Recreational Club Izcaragua (between Caracas and Guatire ), ~ 900 m elev., Jan. 19, 1985 (E. Bardinet & Sobrevila), 13 1 juvenile in USNM .

Mecoloesthus mucuy , new species Figures 1024–1033

TYPES: Male holotype, 73 paratypes from Tabay Mucuy , Mérida, Venezuela ; 2250 m elev., ‘‘ Send. Lag. Suero,’’ cloud forest, June 17–Aug. 2, 1989 (S. & J. Peck), in AMNH .

ETYMOLOGY: Named for the type locality. The specific name is a noun in apposition.

DIAGNOSIS: Distinguished from close relatives ( M. azulita , peckorum ) by the number and position of apophyses on the male chelicerae (fig. 1030), by the shape of the procursus (figs. 1032–1033), and the embolar division of the bulb (fig. 1031).

MALE (holotype): Total length 3.2, carapace width 1.3; leg 1: 21.2 (4.8+0.4+4.9 +9.1+2.0), tibia 2: 3.1, tibia 3: 2.4, tibia 4: 2.9; tibia 1 l/d: 35. Habitus as in fig. 1024; distance PME-ALE about 80% of PME diameter. Carapace dark ochre-brown, darker anteriorly, posteriorly slightly inflated (figs. 1025–1026); ocular area and clypeus brown. Sternum light to dark brown (dark anteriorly); chelicerae ochre and brown in pattern shown in fig. 1030, with three pairs of inward-facing black apophyses (most distal pair just a sclerotized hump) (fig. 1030). Palps as in figs. 1028–1029, coxa with distinct retrolateral apophysis, femur with retrolateral apophysis proximally and ventral projection distally, procursus with prominent proximal protrusion, distally simple (fig. 1032), bulb as in fig. 1031. Legs light brown, with dark rings on femora (subdistally) and tibiae (proximally and subdistally), without spines, without curved and vertical hairs; re- trolateral trichobothrium of tibia 1 at 5%; tarsus 1 with ~ 25 pseudosegments. Opisthosoma as in fig. 1024, very dark bluish.

VARIATION: Tibia 1 in 4 other males: 4.7– 5.4.

FEMALE: Unknown.

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: VENEZUELA: Mérida: Tabay Mucuy: types above.

Mecoloesthus azulita , new species Figures 1034–1037

TYPES: Male holotype from 20 km SE Azulita (‘‘ULA Biol. Res. La Carbonera’’),

Mérida, Venezuela; 2300 m elev., ‘‘ Podocarp forest ,’’ June 28–Aug. 3, 1989 (S. & J. Peck), in AMNH ; 13 paratype from same locality, ‘‘ Podocarp forest , carriontips,’’ June 28–July 27, 1989 (S. & J. Peck), in AMNH .

ETYMOLOGY: Named for the town close to the type locality. The specific name is a noun in apposition.

DIAGNOSIS: Distinguished from close relatives ( M. mucuy , peckorum , tabay ) by the single pair of short, curved, pointed apophyses laterally on the male chelicerae (fig. 1034), by the shape of the procursus (figs. 1036–1037), and the embolar division of the bulb (fig. 1035).

MALE (holotype): Total length 3.0, carapace width 1.3; femur 1: 4.5 (other segments missing), tibia 2: 3.1, tibia 3: 2.5, tibia 4: 3.1. Habitus and prosoma shape as in M. mucuy (cf. figs. 1024–1026); distance PME-ALE about 90% of PME diameter. Carapace dark brown, ocular area and clypeus even darker, sternum brown; chelicerae with pair of short curved apophyses laterally, and pair of tiny black cones (fig. 1034). Palps in general as in M. mucuy (cf. figs. 1028–1029), procursus and bulb as in figs. 1035–1037. Legs light brown, without any rings; without spines, without curved and vertical hairs. Opisthosoma dark greenish.

Leg 1 in male paratype: 21.2 (4.8+0.5 +5.0+8.9+2.0), tibia 1 l/d: 38.

FEMALE: Unknown.

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: VENEZUELA: Mérida: 20 km SE Azulita: types above.

Mecoloesthus peckorum , new species Figures 1038–1039

TYPE: Male holotype from Mérida (‘‘ Telef. Est. La Montaña ’’), Mérida, Venezuela ; 2450 m elev., cloud forest, June 27–July 26, 1989 (S. & J. Peck), in AMNH .

ETYMOLOGY: Named for the collectors of the type material.

DIAGNOSIS: Very closely related to M. azulita , distinguished only by the procursus, which is more slender and has a bent tip (compare figs. 1036–1039), and by the male chelicerae, which are provided with several additional tiny sclerotized cones frontally (arrow in fig. 1034).

MALE (holotype): Total length 2.4, carapace width 1.1. Legs 1 and 2 missing; tibia 3: 2.5, tibia 4: 3.0. Habitus and prosoma shape as in M. mucuy (cf. figs. 1024–1026); distance PME-ALE about 90% of PME diameter. Prosoma brown, sternum slightly lighter; chelicerae with large lateral apophyses as in M. azulita (cf. fig. 1034), but with some additional small black cones frontally (arrow in fig. 1034). Palps in general as in M. mucuy (cf. figs. 1028–1029), procursus as in figs. 1038–1039; bulb as in M. azulita (cf. fig. 1035). Legs light brown, without any rings (as in M. azulita ); without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 at 6%. Opisthosoma dark greenish.

VARIATION: The second male is larger (carapace width 1.4; leg 1: 5.6+0.5+5.7, metatarsus and tarsus missing; tibia 2: 3.7, tibia 3: 2.9, tibia 4: 3.5; tibia 1 l/d: 37), but otherwise not distinguishable.

FEMALE: Unknown.

DISTRIBUTION: Known from two localities in Mérida, Venezuela.

MATERIAL EXAMINED: VENEZUELA: Mérida: Mérida: type above ; Mérida, ‘‘ Hechicera, Monte Zerpa ,’’ 2000 m elev., montane forest, July 22–Aug. 2, 1989 (S. & J. Peck), 13 in AMNH .

Mecoloesthus tabay , new species Figures 1040–1043

TYPE: Male holotype from Mérida (‘‘ Telef. Est. La Montaña ’’), Dept. Mérida, Venezuela ; 2450 m elev., cloud forest, June 27–July 26, 1989 (S. & J. Peck), in AMNH .

ETYMOLOGY: Named for one of the collection sites, Tabay Mucuy Nat. Park. The specific name is a noun in apposition.

DIAGNOSIS: Distinguished from close relatives ( M. mucuy , azulita , peckorum ) by the rounded, inward-facing apophyses on the male chelicerae (fig. 1040), and the shape of the procursus (figs. 1042–1043).

MALE (holotype): Total length 2.8, carapace width 1.2; leg 1: 22.3 (5.1+0.5+5.1 +9.6+2.0), tibia 2: 3.3, tibia 3: 2.5, tibia 4: 2.9; tibia 1 l/d: 38. Habitus and prosoma shape as in M. mucuy (cf. figs. 1024–1026); distance PME-ALE about 90% of PME diameter. Prosoma brown, chelicerae with large rounded lateral apophyses, and another smaller pair (hidden by large apophyses in fig. 1040). Palps in general as in M. mucuy (cf. figs. 1028–1029), procursus and bulb as in figs. 1041–1043. Legs light brown, with dark rings on femora (subdistally), and tibiae (proximally, subdistally), dark rings on femora preceded by light rings; without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 at 5%; tibia 1 with ~ 36 pseudosegments (very distinct!). Opisthosoma dark greenish-gray. (Tibia 1 in other male: 5.3.)

FEMALE: Unknown.

DISTRIBUTION: Known from two localities in Mérida, Venezuela.

MATERIAL EXAMINED: VENEZUELA: Mérida: Mérida: type above ; Tabay Mucuy, ‘‘Send. Lag. Suero,’’ cloud forest, 2700 m elev., June 19–July 24, 1989 (S. & J. Peck), 13 in AMNH .

Mecoloesthus cornutus , new species Figures 1044–1047

TYPES: Male holotype, 33 paratypes from El Valle, 5 km NE Mérida, Mérida, Vene-

zuela; 2400 m elev., cloud forest, June 24– Aug. 2, 1989 (S. & J. Peck), in AMNH.

ETYMOLOGY: The specific name is an adjective referring to the long male cheliceral apophyses.

DIAGNOSIS: Distinguished from congeners by the long curved apophyses laterally on the male chelicerae (fig. 1044), by the shape of the procursus (figs. 1046–1047), and the embolar division of the bulb (fig. 1045).

MALE (holotype): Total length 2.8, carapace width 1.3; leg 1: 23.6 (5.3+0.5+5.5 +10.3+2.0), tibia 2: 3.3, tibia 3: 2.5, tibia 4: 2.9; tibia 1 l/d: 39. Habitus and prosoma shape as in M. mucuy (cf. figs. 1024–1026); coloration and general structure as in M. mucuy ; distance PME-ALE about 80% of PME diameter. Chelicerae with pair of very long curved apophyses laterally, and two pairs of smaller humps frontally (fig. 1044). Palps in general as in M. mucuy (cf. figs. 1028–1029), procursus and bulb as in figs. 1045–1047. Legs as in M. mucuy , but with light rings immediately before and after dark rings; without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 at 5%; tarsus 1 with ~ 30 pseudosegments. Opisthosoma as in M. mucuy , but with dark spots dorsally.

VARIATION: Tibia 1 in 2 other males: 5.0, 5.5.

FEMALE: Unknown.

DISTRIBUTION: Known from four localities in Mérida, Venezuela.

MATERIAL EXAMINED: VENEZUELA: Mérida: El Valle: types above ; Tabay Mucuy, ‘‘ Send. Lag. Suero ,’’ cloud forest, 2250 m elev., June 17–Aug. 2, 1989 (S. & J. Peck), 13 in AMNH ; Mérida, ‘‘ Telef. Est. La Montaña ,’’ 2450 m elev., cloud forest, June 27– July 26, 1989 (S. & J. Peck), 13 in AMNH ; Mérida, ‘‘ Hechicera, Monte Zerpa ,’’ 2000 m elev., montane forest, July 22–Aug. 2, 1989 (S. & J. Peck), 13 in AMNH .

Mecoloesthus yawaperi , new species Figures 1048–1054

TYPES: Male holotype (‘‘T11 N-A’’), 23 paratypes (‘‘T2 N-B,’’ ‘‘T14 N-E’’), from Dimona Reserve , near Manaus, Amazonas, Brazil ; 1989 –1992 (H. G. Fowler), in MCZ .

ETYMOLOGY: The specific name is a noun in apposition honoring the Yawaperi Indians living north of Manaus in Brazil, who have been widely known for their ‘‘aggressiveness’’ in protecting their land and identity.

DIAGNOSIS: Distinguished from congeners by the pair of tiny frontal apophyses on the male chelicerae (fig. 1049), the slender and simple procursus (figs. 1050–1051), and the shape of the ventral apophysis distally on the male palpal femur (fig. 1048).

MALE (holotype): Total length 2.2, carapace width 1.0; leg 1: 27.2 (6.4+0.3+6.7 +11.7+2.1), tibia 2: 3.9, tibia 3: 2.7, tibia 4: 3.5; tibia 1 l/d: 100. Prosoma as in M. mucuy (cf. figs. 1024–1026), but ocular area slightly less elevated, and distance PME- ALE smaller (~ 50% of PME diameter). Carapace ochre-brown, slightly inflated posteriorly but with distinct thoracic groove; clypeus with pair of darker stripes, sternum ochre-brown, without humps. Chelicerae brown, with pair of small apophyses frontally (fig. 1049). Palps as in figs. 1052– 1053, coxa with retrolateral apophysis, femur with retrolateral apophysis proximally and distinct ventral apophysis distally (fig. 1048), procursus simple (figs. 1050–1051), bulb as in fig. 1054. Legs light brown, without rings, without spines and curved hairs; with vertical hairs on metatarsi; retrolateral trichobothrium of tibia 1 at 3%; tarsus 1 with over 30 pseudosegments. Opisthosoma as in M. mucuy (cf. fig. 1024) but slightly longer, pale greenish, with hardly visible darker spots dorsally, ventrally with darker band from genital plate halfway to spinnerets.

VARIATION: Tibia 1 in paratype: 5.7 (missing in other paratype). One male paratype (‘‘T14 N-E’’) with some distinct bluish-white spots and stripes on opisthosoma.

FEMALE: Unknown (a prosoma, possibly of a conspecific female, accompanies the male holotype; it is very similar to the male prosoma, also slightly inflated; tibia 1: 4.3).

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: BRAZIL: Amazonas: Manaus, Dimona Reserve: types above, and female prosoma accompanying holotype.

Mecoloesthus putumayo , new species Figures 1055–1059

TYPE: Male holotype from near Puerto Asis , Rio Putumayo, Dept. Putumayo, Colombia ; no date (W. G. Eberhard), in MCZ. ETYMOLOGY: Named for the Colombian state Putumayo. The specific name is a noun in apposition .

DIAGNOSIS: Distinguished from congeners by the procursus with complicated tip composed of lamellae and apophyses (figs. 1058– 1059), and the male palpal femur with its distinctive ventral apophysis (fig. 1057).

MALE (holotype): Carapace width 1.1, opisthosoma missing; leg 1: 53.9 (12.8+0.5 +12.8+24.9+2.9), tibia 2: 7.1, tibia 3: 5.3, tibia 4: 6.9; tibia 1 l/d: 113. Prosoma slightly damaged, but apparently very similar to M. mucuy (cf. figs. 1024–1026); distance PME- ALE about 80% of PME diameter. Carapace light ochre with large median brown mark and brown lateral margins, slightly inflated posteriorly; clypeus dark brown, sternum pale ochre-yellow. Chelicerae light brown, with pair of blackish apophyses frontally (fig. 1055). Palps in general very similar to M. mucuy (cf. figs. 1028–1029), coxa with retrolateral apophysis, femur with distinct ventral apophysis distally (fig. 1057), procursus with complex tip (figs. 1058–1059), bulb as in fig. 1056. Legs light ochre, distal tips of tibiae light; legs without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 at 1.5%; tarsus 1 with over 35 pseudosegments.

FEMALE: Unknown.

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: COLOMBIA: Putumayo: near Puerto Asis: type above.

Mecoloesthus arima , new species Figures 1060–1068

TYPE: Male holotype from Arima Valley , Trinidad ; 800–1200 ft elev., Feb. 10–22, 1964 (P. Wygodzinski & J. Rozen), in AMNH .

ETYMOLOGY: Named for the type locality. The specific name is a noun in apposition.

DIAGNOSIS: Easily distinguished from congeners by the shape of the procursus (figs. 1065, 1067–1068), the long bulbal apophysis (fig. 1064), the shape of the male palpal femur apophysis (fig. 1066) and the strong apophyses on the male chelicerae (figs. 1060–1061).

MALE (holotype): Total length 2.5, carapace width 1.1, legs 1–3 missing; leg 4: 17.9 (5.0+0.4+4.5+7.0+1.5). Habitus as in fig. 1060; distance PME-ALE about 70% of PME diameter. Carapace orange-ochre, brown medially and laterally, conspicuously inflated posteriorly (figs. 1060–1061, 1063), ocular area brown, clypeus brown, sternum light orange-ochre, with reddish-brown margins (fig. 1062). Chelicerae brown, produced anteriorly into pair of large apophyses (figs. 1060–1061). Palps as in figs. 1064–1065, coxa with retrolateral apophysis, femur with retrolateral apophysis proximally, distinct ventral apophysis distally (fig. 1066), procursus as in figs. 1067–1068, bulb with transparent projection accompanying simple long apophysis (fig. 1064). Legs light brown, femora and tibiae with slightly lighter tips; legs 4 without spines, without curved and vertical hairs; tarsus 4 with ~ 20 pseudosegments. Opisthosoma in holotype shrunken (fig. 1060), in other male (see below) like in M. mucuy (cf. fig. 1024), pale greenish, with distinct black spots arranged in lines, genital plate wide, light brown, short black stripe behind genital plate.

Measurements of other male (see below): carapace width: 1.15; leg 1: 36.5 (8.8+0.4 +8.8+16.5+2.0), tibiae 2 and 4 missing, tibia 3: 3.9; tibia 1 l/d: 110; retrolateral trichobothrium of tibia 1 at 2%; tarsus 1 with over 30 pseudosegments.

FEMALE: Unknown.

DISTRIBUTION: Known only from Arima Valley, Trinidad.

MATERIAL EXAMINED: TRINIDAD: St. George Co.: Arima Valley : type above ; Simla, Arima Valley , Apr. 18, 1964 (A. M. Chickering), 23 in AMNH .

Mecoloesthus hoti , new species Figures 1069–1076

TYPE: Male holotype from Rio Baria , Dept. Amazonas, Venezuela ; ~ 100 m elev., ‘‘from overhead vegetation fell into dugout canoe,’’ July 21, 1984 (L. S. Ford & C. W. Myers), in AMNH .

ETYMOLOGY: The specific name is a noun in apposition honoring the Hotí, an Indian people in the state of Bolívar who have maintained their cultural identity partly by the relative inaccessibility of their territory.

DIAGNOSIS: Easily distinguished from any known pholcid by the bulky male pedipalp (fig. 1075), the uniquely formed procursus (figs. 1073, 1075), and the cheliceral armature (fig. 1076).

MALE (holotype): Total length 2.8, carapace width 1.2; leg 1: 35.2 (8.5+0.4+8.1 +15.5+2.7), tibia 2: 5.1, tibia 3: 3.9, tibia 4: 5.1; tibia 1 l/d: 101. Habitus and prosoma as in figs. 1069–1072. Carapace light brown, inflated posteriorly, but with distinct thoracic groove between inflation and ocular area; eight eyes on moderately elevated ocular area; distance PME-ALE about 50% of PME diameter. Sternum light orange-brown; chelicerae light brown, with two pairs of apophyses, median pair distinctively shaped (fig. 1076). Palps as in figs. 1074–1075, light brown, procursus black; coxa with narrow retrolateral apophysis, femur proximally with rounded retrolateral apophysis, distally with distinct ventral apophysis and sclerotized hump (fig. 1075), procursus bent inwards in sharp angle, with field of sclerotized ridges retrolaterally and large rounded protrusion dorsally (fig. 1073), bulb with slightly spiraling sclerite and semitransparent projection dorsally (fig. 1074). Legs brown with light tips on femora and tibiae; without spines and curved hairs, with some vertical hairs on metatarsi; retrolateral trichobothrium of tibia 1 at 3%; tarsus 1 with over 35 pseudosegments. Opisthosoma ochre-gray, with dark spots dorsally.

FEMALE: Unknown.

DISTRIBUTION: Known only from type locality.

MATERIAL EXAMINED: VENEZUELA: Amazonas: Rio Baria: type above.

Mecoloesthus taino , new species Figures 1077–1089

TYPES: Male holotype, 13 2♀ paratypes from ‘‘ La maison de la Foret,’’ Basse Terre, Guadeloupe, Lesser Antilles ; Aug. 1983 (A. Lopez), in AMNH .

ETYMOLOGY: The specific name is a noun in apposition honoring the Taíno of the West Indies (see Tainonia , p. 145).

DIAGNOSIS: Close relative of M. lemniscatus (Simon) and M. nigrifrons (Simon) , easily distinguished from both by the pair of apophyses on the epigynum (figs. 1087– 1088).

MALE (holotype): Total length 3.9, carapace width 1.5; leg 1: (11.9+0.6+11.6+> 18.1, tarsus missing), tibia 2: 6.7, tibia 3: 4.8, tibia 4: 6.1; tibia 1 l/d: 94. Habitus and prosoma as in figs. 1077–1079. Carapace ochre with brown pattern (fig. 1079), inflated posteriorly, but with distinct thoracic groove between inflated part and ocular area; eight eyes on moderately elevated brown ocular area; distance PME-ALE about 70% of PME diameter. Clypeus with brown pattern (fig. 1078), sternum ochre with brown triangle anteriorly (fig. 1083); chelicerae brown, with two contiguous black apophyses on each side (fig. 1082). Palps as in figs. 1080–1081, ochre to dark brown; coxa with distinct retrolateral apophysis, femur with small retrolateral apophysis proximally and distinct ventral apophysis distally (fig. 1086), pro- cursus with dorsal process subdistally and transparent laminae distally (figs. 1084 – 1085), bulb with flat sclerite dorsally, short spinelike process prolaterally, and a prominent apophysis distally (fig. 1080). Legs light, with slightly darker rings on femora (subdistally) and tibiae (proximally and subdistally); without spines and curved hairs, with some vertical hairs on all segments; re- trolateral trichobothrium of tibia 1 at 2%; tarsus 1 with ~ 30 pseudosegments. Opisthosoma greenish-gray, with large darker spots dorsally, genital plate dark brown; behind genital plate dark band halfway to spinnerets.

VARIATION: Tibia 1 in four males (incl. types): 9.6–11.7; in the paratype the margin of the sternum is darker. The specimens from Dominica are smaller, but the genitalia and chelicerae appear to be identical .

FEMALE (paratypes): Total length 3.9; tibia 1: 9.5, 9.9; prosoma only slightly inflated posteriorly. Epigynum brown, prominent, with pair of anterior apophyses (figs. 1087– 1088), internal genitalia with transparent median blind sac and apparently divided pore plates (fig. 1089; in the KOH preparation it was difficult to see whether both plates are actually provided with the typical pores).

DISTRIBUTION: Known from the Lesser Antilles: Guadeloupe, Dominica; the label in one additional vial reads ‘‘Landat Dom.’’

MATERIAL EXAMINED: GUADELOUPE: Basse Terre : types above. DOMINICA: Fresh Water Lake, 850 m elev., Feb. 4, 1968 (B. Malkin), 13 1♀ in AMNH ; Long Ditton , June 18, 1911 (‘‘M. I.’’), 13 in AMNH ; Clarke Hall , ‘‘molasses jars,’’ Oct. 12, 1966 (A. B. Gurney), 13 1♀ in USNM ; Clarke Hall , Apr. 5, 1965 (D. R. Davis), 13 2♀ in USNM ; l’Eau Goumier , Mar. 13, 1956 (J.F.G. Clarke), 1♀ in USNM .

MNHN

Museum National d'Histoire Naturelle

AMNH

American Museum of Natural History

USNM

Smithsonian Institution, National Museum of Natural History

MCZ

Museum of Comparative Zoology

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Loc

Mecoloesthus

HUBER, BERNHARD A. 2000
2000
Loc

Mecoloesthus longissimus

Simon 1893: 320 - 321
1893
Loc

Mecoloesthus longissimus

Simon. 1019
1019
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