Corasoides nebula, Humphrey, 2017

Humphrey, Margaret, 2017, A Revision and Cladistic Analysis of the Genus Corasoides Butler (Araneae: Desidae) with Descriptions of Nine New Species, Records of the Australian Museum 69 (1), pp. 15-64 : 43

Corasoides nebula sp. nov.

Figs 22 , 23

Holotype ♂, Ambua Lodge 25 km SE Tari, SHP, 5°58'S 143°04'E, 2100 m, PAPUA NEW GUINEA, Nov. 1996, M. Humphrey, KS.71840 ( AM) . Paratypes as follows, all Papua New Guinea: 2♂♂, 2♀♀, same data as holotype, KS.71841 ( AM) .

Other material examined. 5 juveniles, 4 epigynes, same data as holotype ( AM) .

Diagnosis. CL less than 3.0 mm. Male with enlarged anterior, retrolateral cheliceral teeth ( Fig. 23b ). Retrolateral apophysis with fine spine-like apex ( Fig. 22a,b ). Can be distinguished from the closely related C. cowanae sp. nov. by the absence of a dorsal tibial process on the male palp, by the wide scape in the female and highly convoluted but uncoiled insemination ducts ( Fig. 23d,e,f ).

Description. Small spider. Carapace. Light cream with faint grey pattern. Other specimens with darker grey pattern. Edged with dark grey except in petiole region. Abdomen. In holotype dark; central grey stripe and spots indiscernible. Dorsolateral stripes to anterior half of abdomen but thin. In other specimens spots are discernible and dorsolateral stripes wider but shorter.

Male ( Figs 22 , 23a,b,g ). CL 2.4 (2.6), CW 1.9 (1.8), AL 1.8, AW 1.2, HW 1.2, EpGW 0.9, MOQL 0.48, MOQAW 0.34, MOQPW 0.44, SL 1.2, SW 1.2, ML 0.9, MW 0.5, LL 0.5, LW 0.4, ChelL 1.7 (1.9), ChelW 0.6 (0.8), clypeus height 0.2. Cephalothorax. Sternum equal in width and length, posterior point blunt. Labium width and length roughly equal, notched basally. Chelicerae. Long. Boss insignificant. Cheliceral teeth: retromarginal 6–8, anterior tooth greatly enlarged; promarginal 4. No transverse ridges between teeth margins. Fangs wide, robust, angular, without serrations. Dark banding on legs. Leg lengths:

I II III IV Palp femur 5.4 3.9 5.0 1.6

patella 1.0 0.8 1.0 0.5

tibia 5.1 2.6 4.1 0.5 metatarsus 5.7 4.0 6.2 —

tarsus 3.0 1.8 2.5 2.1

total 20.1 13.1 18.8 3.1

Spination (on leg II from paratype). Leg I: femur d1,1,1,2; tibia v1,1,1,2; metatarsus v2,2,2,2. (Leg II: femur d113; tibia v112; metatarsus v112). Leg III: femur d1,2,1,2,1,2,1,2; patella d1; tibia d1,2,2,2 r1; metatarsus d1,1,1,1,12 v1,1,1,1,2. Leg IV: femur d1,1,2,1,1,2; tibia 1,1,1,1,1 p1 r1,1; metatarsus d1,2,2,2,2,1,2 v1,2,2,2,2,2; Palp: femur d1,1,3; patella d1,1; tarsus several. Male palp. Digitiform portion of cymbium moderately long, cymbium length approximately three times diameter of bulb. Retroventral apophysis absent. Ventral apophysis erect, curled on lateral edge, not enclosing any intersegmental membrane. Retrolateral apophysis robust, with curved basal portion, spine-like portion fine, curved, pointing away from bulb retrolaterally. Trichobothria on cymbium indistinct, 2–5. Abdomen. No tail of small spigots on anterior lateral spinnerets.

Female ( Fig. 23c–g ), similar to male. CL 2.4 (2.1), CW 1.8 (1.6), AL 2.4, AW 1.6, HW 1.0, EpGW 0.7, MOQL 0.4, MOQAW 0.3, MOQPW 0.4, SL 1.1, SW 1.2, ML 0.8, MW 0.4, LL 0.4, LW 0.4, ChelL 1.6 (1.2), ChelW 0.7 (0.6), clypeus height 0.5. Chelicerae. Boss small. Cheliceral teeth 8(7), 2(4), without enlargements as in male. Legs darkly banded. Leg lengths:

I II III IV Palp femur 3.8 2.8 2.4 3.5 1.2

patella 0.8 0.7 0.7 0.7 0.4

tibia 3.7 2.2 2.5 2.8 0.8 metatarsus 3.5 2.4 2.5 3.7 —

tarsus 2.1 1.4 1.5 1.6 1.3

total 13.8 9.6 9.6 12.3 3.6

Spination. Leg I: femur d1,1,2; tibia d1; metatarsus v2. Leg II: femur d1,1,1,3; tibia d1 v1,2; metatarsus v1,2. Leg III: femur d1,1,1,3; patella d1; tibia d1,1,1, v2; metatarsus d2,2,2,2 v1,2 r1. Leg IV: femur d1,1,1,1,1,1,4; patella d1; tibia d1,1,1,3,2 v2 r1,1; metatarsus d2,2,2,2 v1,2. Palp: femur d1,1; patella d1,1; tibia d1,1; tarsus several. Trichobothria on 1st tarsus: single row of 5, decreasing in length proximally. Epigyne ( Fig. 23c ). Wider than long. Smooth, with beak projecting posteriorly over anterior of scape stalk. Scape stalk wide, approximately equal to diameter of one genital atrium. Genital atria and openings situated in posterior half of epigyne. Lateral margin of lateral extensions of scape indiscernible. Insemination ducts strongly convoluted but with no coils (c. 9 bends) ( Fig. 23e,f ). Spermathecae well separated ( Fig. 23d ).

Habitat. Tropical rainforest, 2100 m. Webs were common projecting from damp earthen slopes and embankments where retreats were sited in crevices or amongst leaf litter.

Distribution. Known only from holotype locality, 25 km south east of Tari, Papua New Guinea ( Fig. 23g ).

Etymology. From the Latin nebula , meaning mist or fog and referring to the mist forest inhabited by this species.

Figures

Figure 22. Corasoides nebula sp. nov., male: (a) palpal

Figure 23.Corasoides nebula sp. nov.:(a) cheliceral teeth;(b) chelicerae, ventral;(c) epigyne, ventral;(d) female internal genitalia, dorsal; (e) female internal genitalia, dorsal exploded view; (f) female genitalia, lateral, from centre; (g) distribution.