Perania nasicornis Schwendinger, 1994

Schwendinger, Peter J., 2013, A taxonomic revision of the spider genus Perania Thorell, 1890 (Araneae: Tetrablemmidae: Pacullinae) with the descriptions of eight new species, Revue suisse de Zoologie 120 (4), pp. 585-663 : 600-603

Perania nasicornis Schwendinger, 1994 Fig. 2M-P

Perania nasicornis Schwendinger, 1994: 448-452 , figs 1-14 (description of male and female). – Platnick, 2013 (listing).

HOLOTYPE: MHNG; 1 Ƌ; Thailand, Lamphun Province, Mae Tha District, Doi Khuntan (18°29’23”N, 99°17’55”E), 1250 m; 16.II.1992; leg P. J. Schwendinger.

PARATYPES: MHNG; 6 Ƌ, 4 ♀; from the type locality, 1000-1300 m; 6.II.1992, 8.X.1992, leg. P. J. Schwendinger. No additional material available .

DIAGNOSIS: See Schwendinger (1994: 448).

NEW CHARACTERS: Anterior opisthosomal plate of females fragmented into microplates of different sizes. Postgenital plate in all males completely fused to posterior margin of pulmonary plate, with a sclerotised suture linking them; all microplates on posterior side of opisthosoma of males close to each other but not fused into horizontal strap-like plates. Anterior pair of ventrolateral plates of males largely free, only posterior tips fused with pulmonary plate. Preanal plate of females fragmented into microplates, some of the posterior ones slightly wider than the others. Apex of embolus distinctly split, with widely rounded subterminal lamella overlapping pointed embolic part with a quite large, lobate dorsal projection (Fig. 2M-N). Vulva with posterior dorsal margin of anterior collar very widely rounded (unlike in P. birmanica ); spermathecae with lateral sides distinctly bulged in posterior portion (Fig. 2O).

REMARKS: The porepatches of all spermathecae are much larger than illustrated in the original decription (Fig. 2O-P cf. Schwendinger, 1994: figs 13-14), extending on the lateral sides down to the posterior corners of the spermathecae (but usually not visible in ventral view because hidden behind the bulged posterolateral corners). This and the following two new observations on P. nasuta make the distinction between females of P. nasicornis and P. nasuta more difficult than given in the original description. Not all P. nasuta females have a longer anterior collar of the vulva than females of P. nasicornis (Fig. 2K cf. Fig. 2O). Perania nasuta females from Doi Suthep-Pui have spermathecae that are posteriorly slightly wider than anteriorly (Fig. 2K). Thus females of both species can be more reliably distinguished by the following: Perania nasuta with more or less distinctly elevated conical microplates behind dorsal scutum of opisthosoma (microplates not elevated in P. nasicornis ); spermathecae posteriorly narrower or slightly wider than anteriorly (distinctly wider in P. nasicornis ), their lateral margins not bulging outwards in posterior portion (distinctly bulged in P. nasicornis ), pores visible along most of lateral sides in ventral view (pores hidden by bulged posterolateral corner in ventral view in P. nasicornis ) (Fig. 2K cf. Fig. 2O). Differences were also found in the sizes of the fragments (microplates) of the anterior opisthosomal plates of females: in P. nasicornis two lateral, one central and all dorsal fragments (corresponding to the upper margin of the plate) are clearly larger than the remaining microplates; in P. nasuta only the two lateral fragments are enlarged. However, the latter differences are not pronounced and cannot be used as a reliable distinction between females of both species. They therefore have not been used in the key to the species.

DISTRIBUTION: Known only from a mountain in northern Thailand (Fig. 1, locality 11).

Perania birmanica ( Thorell, 1898) Fig. 3 Paculla birmanica Thorell, 1898: 282-283 (description of ♀). Perania birmanica ( Thorell, 1898) . – Bourne, 1980: 256-259, figs 20-23 (re-description and

illustration of holotype; transfer); Lehtinen, 1981: 16 (mention; transfer); Schwendinger,

1989: fig. 21 (illustration of outlines of spermathecae); Platnick, 2013 (listing).

HOLOTYPE: MCSN; ♀; “ Birmania, Carin Ceba , Biapó ” [on original labels], “ Carin Chebà ” or “ Bia-pó ” mountains [in original description], approximally 19°05’N, 96°35’E; 1885-1889; leg. Leonardo Fea.

DIAGNOSIS: Female holotype (male unknown) distinguished from females of other congeners by a dorsal opisthosomal scutum with a quite regularly eliptical margin (Fig. 3C; Bourne, 1980: fig. 21), and by largely fused spermathecae with a flat common ventral surface, a widely arched common anterior margin and distinct trenches in anterior and lateral sides.

FIG. 3

Perania birmanica Thorell, 1898 , female holotype. (A) Anterior portion of carapace, dorsal view. (B) Same, lateral view. (C) Dorsal scutum of opisthosoma, dorsal view. (D) Vulva, dorsal view. (E) Same, ventral view. (F) Same, anterior view. Abbreviation: t = trench. Scale lines 1.0 mm (A-B; C), 0.5 mm (D-F).

NEW CHARACTERS: Vulva with ventral side uniformly pigmented (no unpigmented zone between spermathecae and genital atrium; Fig. 3D-E) and uniformly flat (spermathecae not bulged; Fig. 3F). Vulva similar to that of P. ferox sp. n., distinguished by left and right spermathecae without depression or unpigmented zone between them; anterior and lateral sides of spermathecae with narrow porepatches lying in distinct trenches (Fig. 3F); anterior collar with deep median invagination in posterior margin (Fig. 3D; possibly a condition of the holotype and not a character of the species). Outlines of the holotype’s spermathecae shining through the intact genital plate illustrated by Schwendinger (1989: fig. 21). Preanal plate fragmented into microplates, the three posterior ones laterally connected with each other. Anterior opisthosomal plate completely fragmented.

RELATIONSHIPS: Strong similarities in copulatory organs of females and close geographical proximity indicate that P. birmanica is closely related to P. ferox sp. n. and P. quadrifurcata sp. n. Therefore it is quite likely that the unknown male of P. birmanica also has a long clypeal process. Lehtinen (1981: 16) speculated that P. birmanica could be close to P. armata from Sumatra, because Thorell (1898) compared the first with the second species, but there is no evidence for a close relationship between them.

DISTRIBUTION: Known only from the type locality in the mountains of the Karen (= Kayin) State, northeast of Toungoo (Fig. 1, locality 12). This area has been off limits to foreign visitors without a special permit for the last four and a half decades .