Cheiracanthium truncatum ( Thorell, 1895 )

Esyunin, Sergei L. & Zamani, Alireza, 2020, ‘ Conundrum of esoterica’: on the long-forgotten genus Eutittha Thorell, 1878, with new taxonomic considerations in Cheiracanthium C. L. Koch, 1839 (Araneae: Cheiracanthiidae), Journal of Natural History (J. Nat. Hist.) 54 (19 - 20), pp. 1293-1323 : 1308

Cheiracanthium truncatum ( Thorell, 1895)

Eutittha truncata Thorell, 1895, p. 48 (conditional name for ♀ described under Eutittha gracilipes , description of ♀ syntypes from MYANMAR: 70 miles north of Eaugoon , Thayarwaddy; E. W. Oates leg. 1884–1887). Cheiracanthium truncatum: Dankittipakul & Beccaloni 2012, p. 81 , figs 10, 12 (♀).

Comments

This species is known from two female specimens from Myanmar (= Burma) . One was described and provisionally identified by Thorell as E. gracilipes (with conditional mention of the name E. truncata ), the second, which is ‘labelled E. melanostoma (from Palon, identified by Thorell)... has proved to be E. truncata ’, was identified by Dankittipakul and Beccaloni (2012, p. 82). The same authors, who examined the female described by Thorell, came to the following conclusion: ‘this female is regarded as a valid taxon and separated from that of E. gracilipes ’ ( Dankittipakul and Beccaloni 2012, p. 81) .

We agree with Dankittipakul and Beccaloni (2012, p. 82) that the epigyne of C. truncatum is very similar to that of C. fibrosum Zhang, Hu & Zhu, 1994 from Hunan Province, China and that the latter species is possibly a junior synonym of C. truncatum . Regardless, this pair of species belong to the East Asian truncatum species group of Cheiracanthium , which includes C. truncatum , C. eutittha Bösenberg & Strand, 1906 , C. fibrosum , C. murinum , C. pichoni Schenkel, 1963 , C. uncinatum Paik, 1985 , and C. unicum Bösenberg & Strand, 1906 . It is possible that C. taiwanicum Chen, Huang, Chen & Wang, 2006 which has a uniquely shaped epigyne also belongs to this group. This species group is characterised by the following characters: (1) tibia of male palp with PTA, RTA and DTA; DTA large, well developed in C. fibrosum , C. murinum , C. uncinatum and C. unicum but in the form of a small knob in others; (2) TA in the form of an elongated droplet (expanded at the base) is more or less S-shaped; (3) epigyne with chitinized anterior margin and lateral margins, whereas posterior margin of epigyne unclear; (4) CD is simple (except for C. taiwanicum ); (5) final chamber of spermathecae spherical. This combination of characters indicates that none of the species of the truncatum group is conspecific with Eutittha .