Dolichognatha albida (Simon)

Smith, Helen M., 2008, Synonymy of Homalopoltys (Araneae: Araneidae) with the genus Dolichognatha (Araneae: Tetragnathidae) and descriptions of two new species, Zootaxa 1775, pp. 1-24 : 11-15

Dolichognatha albida (Simon)

Figs 17–28

Homalopoltys albidus Simon 1895: 894 . Holotype Ψ, Sri Lanka, Colombo. In MNHNP, No.16281, examined. NEW COMBINATION.

Other material examined. THAILAND: (Central Thailand) 3 Ψ, RMNH (ex coll. CLD), Khao Yai National Park, 5.iii.1986, C.L. & P.R. Deeleman, c. 1000 m, in big horizontal web between leaves, no hub; 2 j, RMNH (ex coll. CLD), similar location data, ‘near waterfalls’; 1 j, RMNH (ex coll. CLD), Erewan Waterfalls National Park, 15–16.iii.1986, C.L. & P.R. Deeleman, evergreen.

Comments. The female from Colombo discussed here is believed to be the type of H. albidus , but in the publication the location is given only as “Ins. Taprobane ”. For this species there is no contradiction, merely less information than on the specimen label. But in the case of H. incanescens (below), where the town locality is in disagreement with the original description, one of the additional specimens present in the H. albidus vial provides circumstantial evidence supporting the type status of these Homalopoltys specimens. This specimen is a subadult male Poltys C.L. Koch , likely to be the Poltys ‘male’ from Sri Lanka Simon described in the same paper (1895: 891, fig. 955). Simon’s illustration and his statement that the male lacked a paracymbial hook (which would have been quite obvious in an adult male Poltys, Smith 2005 fig. 10) are indications that the specimen Simon discussed was indeed sub-adult.

Diagnosis. Female. Abdomen apically with ‘drip’ point ( Figs 19, 25 ); copulatory openings on epigynum set away from posterior margin in ventral view, ducts make a horseshoe shape ( Fig. 26 ).

Male. Unknown.

Description. Female (holotype). Carapace ( Figs 17, 20, 21 ): length 0.96 (range 0.88–0.98), width 0.73, height 0.55; carapace humped, broadly pear-shaped in dorsal view, caput poorly differentiated in outline but strongly domed. Chelicerae ( Figs 17, 23 ): promargin bears two definite teeth plus large intermediate where rows meet; retromargin bears one large and 4 small teeth grouped distally. Labium: distinctly mounded anteriorly. Sternum ( Fig. 23 ): strongly convex, especially anteriorly. Eyes ( Figs 17, 20, 21 ). AME: 0.10, PME: 0.08, ALE: 0.07, PLE: 0.08, AME–AME: 0.035, AME–ALE: 0.04, PME–PME: 0.04, PME–PLE: 0.06, ALE–PLE: 0.025; no reflective tapeta visible in type specimen, but visible in some females from Thailand. Legs. I: 3.51, II: 3.04, III: 1.73, IV: 2.20; femur I with one strong plus second weaker prolateral macrosetae at mid point ( Fig. 22 ), distal dorsal macroseta missing. Abdomen ( Figs 18, 19 ): length 2.29, width 1.18; anterior bluntly pointed, point more gently attenuated in Thai specimens ( Figs 24, 25 ), tip often wrinkled; post genital mound strongly produced, posterior surface distinctly flattened. Epigynum ( Figs 26, 27 ): copulatory openings set away from posterior margin in ventral view, ducts viewed through cuticle make a horseshoe shape; in posterior view the internal margins of the lateral plates diverge gradually towards copulatory openings. Internal genitalia ( Fig. 28 ): robust copulatory ducts pass anteromedially around spermathecae to enter posterodorsally; spermathecae with globular head, posterior part hidden by copulatory ducts. Colour in alcohol: creamy-white, traces of dark colouring on dorsal carapace and around eyes; dark coloration more extensive on recent specimens, but still lack any sign of leg stripes. Abdomen pale except for darker spot on posterior flat of post-genital mound; recent specimens have traces of pattern dorsally and anterior tip with traces of black.

Distribution. Dolichognatha albida is recorded from localities in Thailand and Sri Lanka.

Dolichognatha deelemanae sp. n. Figs 29–37

Holotype. INDONESIA: Kalimantan: ɗ, RMNH.ARA.11299 (ex coll. CLD), SE Kalimantan, Meratus Mtn, E of Lake Riam Kanan, 3.vii.1980, C.L. & P.R. Deeleman, primary forest. Paratypes. INDONESIA: Kalimantan: 1 ɗ, RMNH.ARA.11300, 1 Ψ, RMNH.ARA.11301, data as holotype.

Etymology. The specific epithet honours Christa Deeleman-Reinhold, who collected the specimens which originally sparked interest in this group.

Diagnosis. Male. Palpal bulbus short and rounded ( Figs 33, 34 ), abdomen with apical ‘drip’ point ( Fig. 31 , may vary), palpal tibia almost as wide as long, MEA broadens only slightly distally.

Female. Abdomen apically with point, copulatory openings of epigynum set almost on posterior margin in ventral view, ducts shorter than in D. albida ( Fig 35 c.f. Fig. 26 ), internal genitalia delicate ( Fig. 37 , c.f. D. albida , Fig. 28 ).

Description. Male (holotype). Carapace ( Fig. 29 ): length 0.78 (range 0.78–0.80), width 0.61, height 0.39; caput strongly humped in lateral view; similar to D. mandibularis in dorsal view; caput margins produced to distinct projections anterolaterally over cheliceral bases (arrowed in Fig. 32 ). Chelicerae ( Figs 29, 32 ): paturon length shorter than in other species (c. 0.8 × carapace length), basal ledge strongly produced, two distinct promarginal cheliceral teeth and one large intermediate, which is the largest tooth, three retromarginal teeth, basal mound absent; cheliceral fangs shorter than other species, and not sinuous, tips arced. Labium: with distinct, but rather recumbent, spur ( Fig. 29 ). Sternum: distinctly convex ( Fig. 29 ). Eyes ( Figs 29, 32 ). AME: 0.10, PME: 0.08, ALE: 0.065, PLE: 0.065, AME–AME: 0.04, AME–ALE: 0.025, PME–PME: 0.04, PME– PLE: 0.06, ALE–PLE: 0.025; no reflective tapeta visible in either male. Legs: I: 3.76, II: 3.12, III: 1.67, IV: 2.24; femur I with strong prolateral macroseta at mid point, femur II with single retrolateral macroseta at c. ¾ length; front femurs with at least one distal dorsal macroseta as in other species. Abdomen: length 1.94, width 0.86; apex produced into drip-shaped apex ( Fig. 31 ); post-genital mound strongly developed but without coloration ( Fig. 30 ). Palpal organ ( Figs 33, 34 ): palpal femur 0.29× carapace length; patella without macroseta, tibia short compared to other species, distally almost as wide as long; embolus a curved rod; MEA relatively slender, only slightly broadened distally; overall shape of bulbus similar to D. mandibularis , width: length = 1:1.5. Colour in alcohol: almost entirely creamy-white; median eyes with black around margins; faint trace of colour on dorsal carapace.

Female (RMNH.ARA.11301). Carapace: length 0.86, width c. 0.55 (slightly squashed), height c. 0.41; caput strongly domed, sides bulging. Chelicerae: promargin with two definite teeth plus large intermediate where rows meet; retromargin with one large and 4 small teeth grouped distally (rather indistinct). Labium: mounded on anterior face. Sternum: deep, strongly convex. Eyes. AME: 0.10, PME: 0.07, ALE:0.065, PLE: 0.07, AME–AME: 0.02, AME–ALE: 0.03, PME–PME: 0.04, PME–PLE: 0.065, ALE–PLE: 0.03; no reflective tapeta visible (specimen not in good condition). Legs: I: 3.29, II: 2.94, III: 1.57, IV: 2.12; macrosetae near midpoint of prolateral femur I and 4/5 length of retrolateral femur II. Abdomen: length 1.14, width N/A (squashed); attenuated anterior tip not very well developed, moderately developed post-genital mound. Epigyne: copulatory openings set almost on posterior margin in ventral view, ducts viewed through cuticle short and curved into a flattened bowl shape ( Fig. 35 ); in posterior view the internal margins of the lateral plates diverge sharply towards the copulatory openings ( Fig. 36 ). Internal genitalia ( Fig. 37 ): as D. albida but distinctly delicate. Colour in alcohol: creamy-white, traces of dark colouring on dorsal carapace and around eyes. Abdomen pale.

Distribution. Dolichognatha deelemanae is only recorded from south-eastern Kalimantan.

Figures

FIGURES 17 – 28. Dolichognatha albida. 17 – 23, female (holotype). 17, prosoma, lateral. 18, 19, abdomen lateral, dorsal. 20, part of prosoma, frontal. 21, carapace, dorsal. 22, left leg one showing prolateral macrosetae. 23, prosoma, ventral. 24, 25, female (RMNH), abdomen lateral, dorsal. 26 – 28, female epigynum (holotype). 26, ventral. 27, posterior. 28, dorsal (internal genitalia). Scale lines 0.5 mm for somatic parts, 0.1 mm for genitalia.

FIGURES 29 – 37. Dolichognatha deelemanae. 29 – 34, male (holotype). 29, prosoma, lateral. 30, 31, abdomen lateral, dorsal. 32, carapace and chelicerae, frontal; anterolateral carapace projection arrowed. 33, 34, male palpal organ (holotype), ventral, retrolateral. 35 – 37, female epigynum (RMNH. ARA. 11301). 35, ventral. 36, posterior. 37, dorsal (internal genitalia). Scale lines 0.5 mm for somatic parts, 0.1 mm for genitalia.