On the taxonomic validity of Indian ground spiders: II. Genera Drassyllus Chamberlin, 1922 and Nodocion Chamberlin, 1922 (Araneae: Gnaphosidae)

Indian species of Drassyllus and Nodocion are revised, mostly based on the type material available in the National Zoological Collection, Zoological Survey of India, Kolkata. All the Indian representatives of the former genus are transferred to Cryptodrassus, with a synonymy of Drassyllus jabalpurensis syn. nov. with Cryptodrassus khajuriai comb. nov., while the Indian species of the latter genus are transferred to Setaphis, with a provisional transfer of Nodocion solanensis. All the examined type specimens are imaged and supplementary descriptions are provided.


Introduction
to Setaphis Simon, 1893 and synonymized with Setaphis browni (Tucker, 1923) (Platnick & Murphy 1996). All the Indian species of Drassyllus and Nodocion are known from the females only and are poorly described and illustrated, making their identifi cation diffi cult. Moreover, the original illustrations of all these species are clearly differing from the generic features and female genital morphology of the type species of both genera, indicating the possibility of misplacement of Indian representatives under these genera. To clarify the taxonomic ambiguity on Indian species of Drassyllus and Nodocion and to make their identity more transparent, we examined the types of these species available in the National Zoological Collection, Zoological Survey of India, Kolkata and the results are presented below.

Material and methods
The specimens were studied under a Leica EZ4 HD stereo microscope. All measurements are in millimetres (mm). Lengths of palp and leg segments are given as: total (femur, patella, tibia, metatarsus (except for palp), tarsus). The micrographic images were taken with a Leica DFC500 digital camera attached to a Leica M205A stereo microscope with the software package Leica Application Suite (LAS, ver. 3.8) for stacking images taken at different focal planes.

ALE
= anterior lateral eye AME = anterior median eye PLE = posterior lateral eye PME = posterior median eye I-IV = 1 st to 4 th leg NZC-ZSI = National Zoological Collection, Arachnida Section, Zoological Survey of India, Kolkata

Male
Unknown.

Justifi cation of the transfer
Tikader & Gajbe (1976)  PMEs largest, irregular, all other eyes round, cheliceral promargin with three and retromargin with one tooth and epigyne with wide, anterior atrium. Considering these observations, we propose to transfer D. khajuriai to Cryptodrassus.

Justifi cation of the synonymy
A detailed examination of the holotype of D. jabalpurensis shows that it has diagnostic features of D. khajuriai: triangular epigynal atrium with single anterior hood, highly coiled obliquely twisted copulatory ducts with thick proximal and narrow distal parts and spherical and contiguous receptacles (compare Fig. 1C-D with Fig. 2C-D). Based on these observations, we propose to consider D. jabalpurensis as a junior synonym of D. khajuriai.

Remarks
The ZSI collection has one glass bottle for D. khajuriai, labeled as 'holotype' (5043/18), containing a female specimen in fairly good condition, with only left leg II. The same bottle has a small glass vial containing the dissected epigyne. The ZSI collection has one glass bottle for D. jabalpurensis, labeled as 'holotype' (with no register number), containing a female specimen in bad condition. The same bottle has a small glass vial containing the dissected epigyne. (Tikader, 1982) comb. nov.

Male
Unknown. Tikader (1982) described this species on the basis of a female specimen collected in Maharashtra. Like the former species, it has resemblance to Drassyllus spp. only in the posterior median eyes (Fig. 3B). A detailed examination of the holotype of D. mahabalei revealed that it has all of the characteristic features of Cryptodrassus spp. as noted in the case of previous species. Thus we propose to transfer D. mahabalei to Cryptodrassus.

Remarks
The ZSI collection has one glass bottle for this species, labeled as 'holotype' (5044/18), containing a female specimen in good condition, without right leg IV only. The same bottle has a small glass vial containing the dissected epigyne. (Gajbe, 1987) comb. nov. Gajbe, 1987: 289, fi gs 1-5.

Justifi cation of the transfer
Even though we did not examine the type of D. platnicki, which may either be lost or misplaced somewhere in the collection, this species agrees with Cryptodrassus spp. in generic features such as obliquely placed, large, contiguous PMEs, cheliceral promargin with three and retromargin with single tooth and epigyne with anteriorly placed atrium. All these indicate that this species in fact belongs to Cryptodrassus. The structure of vulvae of this species looks closely similar to the vulvae of C. khajuriai comb. nov., suggesting a possible synonymy of the former species with the latter one (compare SANKARAN P.M. et al., Taxonomy of Indian species of Drassyllus and Nodocion (Araneae) Figs 1C-D, 2C-D with Gajbe 1987: fi gs 3-4); however, confi rmation requires the examination of the type or topotype materials of C. platnicki comb. nov.

Diagnosis
Cryptodrassus ratnagiriensis comb. nov. can be distinguished from all other known species of Cryptodrassus by a disto-medially placed small, circular epigynal atrium and uniformly thick, C-shaped copulatory ducts that are confronting each other ( Fig. 4C-D).

Male
Unknown. Tikader & Gajbe (1976) described this species on the basis of a female specimen collected in Maharashtra. Like all the former species, this species also resembles Drassyllus spp. only in the posterior median eyes (Fig. 4B). A detailed examination of the holotype of D. ratnagiriensis revealed that its features fi t those of Cryptodrassus spp. as noted for previous species. We therefore propose to transfer D. ratnagiriensis to Cryptodrassus.

Justifi cation of the transfer
Although we could not examine the type of L. tikaderi, this species agrees with Setaphis in generic features such as PME largest and irregularly rectangular, epigyne with anterior margins, epigynal midpiece surrounded by median ridges and highly twisted copulatory ducts (Platnick & Murphy 1996). All these suggest that this species belongs to Setaphis. The original illustrations of the epigyne of this species show a close resemblance with that of S. browni in the shape of epigynal mid-piece, the path of internal ducts and the shape and orientation of the receptacles, indicating its possible synonymy with the latter species (compare Gajbe 1993: fi gs 3-4 with Fig. 6C-D). However, confi rmation requires the examination of the type or topotype materials of S. tikaderi comb. nov..

Remarks
We found the holotype bottle of L. tikaderi in the arachnid collection of ZSI. However, it did not contain the holotype female; instead it contains a juvenile gnaphosid specimen, indicating that the holotype of L. tikaderi may either be lost or misplaced somewhere in the collection. We found the holotype bottle of Liodrassus mandae Tikader & Gajbe, 1977 in the arachnid collection of ZSI (Fig. 6). The glass bottle, labeled as 'holotype' (5018/18), contains a female specimen in fairly good condition, with broken legs except the fi rst pair. The same bottle has a small glass vial containing the dissected epigyne.

Diagnosis
"Setaphis" solanensis comb. nov. resembles Setaphis subtilis (Simon, 1897) in having a large, fl at proximal part of the copulatory ducts, but can be distinguished by the narrow, highly twisted distal part of the copulatory ducts (copulatory ducts of S. subtilis with broad, uncoiled distal part) (compare

Male
Unknown. Tikader & Gajbe (1977) described this species on the basis of a female specimen collected in Himachal Pradesh. The original illustration of the epigyne of this species (Tikader & Gajbe 1977: fi g. 6b) clearly deviated from the epigyne of Nodocion mateonus Chamberlin, 1922(Platnick & Shadab 1980: fi gs 3-4), indicating its misplacement under Nodocion Chamberlin, 1922. Detailed examination of the holotype of N. solanensis revealed that its features do not fi t those of any known gnaphosid genera, indicating that this species probably represents an unknown Indian gnaphosid genus. However, this will not be confi rmed until the male pedipalp of this species will have been examined. Until then, we tentatively place this species in Setaphis due to the distant similarities in the following features: PMEs irregular, epigyne with a mid-piece and highly twisted internal ducts with wide proximal part ( Fig. 5B-D).

Remarks
The ZSI collection has one glass bottle for this species labeled as 'holotype' (5002/18), containing a female specimen in fairly good condition, with broken legs and detached opisthosoma. The same bottle has a small glass vial containing the dissected epigyne.

Discussion
Even though the gnaphosid spiders described from India are numerically rich, the majority of them are known from poor descriptions and illustrations. A recent revision of the Indian species that had been attributed to the Nearctic genus Scopoides Platnick, 1989 clearly indicated the misidentifi cation of Indian gnaphosid spiders (Sankaran et al. 2019). The present study provides further clarifi cation to the taxonomy of the Indian gnaphosid fauna and strengthens the need of a thorough revision of all the known Indian gnaphosid spiders, in order to obtain clarity on the actual diversity of gnaphosid fauna in India.