A new species of the basal araneomorph spider genus Ectatosticta (Araneae, Hypochilidae) from China

Th e hypochilid spider Ectatosticta davidi (Simon) is redescribed on the basis of adults from Mt. Taibaishan in Shaanxi Province, China; the specimens from Qinghai Province previously identifi ed as E. davidi by most modern authors belong to a new species described as E. deltshevi.


Introduction
Th e spiders of the family Hypochilidae have long been recognized as the most primitive of all araneomorph, or true, spiders.In modern cladistic analyses, they appear as the sister group to all other araneomorphs (Platnick 1977;Forster et al. 1987;Griswold et al. 2005).
Only two genera of hypochilids are known, Hypochilus Marx from the United States, and Ectatosticta Simon from China.Although 10 species of Hypochilus are now recognized, for Ectatosticta only the type species, E. davidi (Simon, 1888), has been described, and that species has been known from only a few specimens.
Even the type locality of E. davidi is problematic.In the original description, Simon (1888) indicated that the male and female syntypes were collected by A. David from "Montagnes au nord de Péking".Th ose specimens are now labeled only "Sina", but Simon (1892) later listed the species as being from "China merid."(southern China), which hardly describes areas north of Beijing.Many decades ago, one of Simon's female specimens from "Inkiaphou" in Shaanxi Provice, China, was donated to Dr Willis Gertsch; the label with that specimen reads "Inkiaphou, Chine méridionale, Mus.Nat.d'Hist.Nat.coll.E. Simon".According to Schenkel (1963: 8), A. David collected at "Inkia-fu, Süd Schensi" in 1873.Repeated attempts by Chinese colleagues to recollect the species in the mountains north of Beijing have all been unsuccessful; Forster et al. (1987: 24) therefore concluded that the syntypes were probably collected at Inkiaphou.Th e exact location of Inkiaphou (in French) or Inkia-fu (in German) is also uncertain, but those names might refer to Inkiapo, now known as Yinjiapo (on Mt.Qinling) in Shaanxi (near 34°00'N, 108°00'E).
Th e redescription and illustrations of E. davidi provided by Forster et al. (1987) and other modern authors were based primarily on specimens taken in Qinghai Province, to the west of Inkiaphou.Th e collection of a good series of specimens, by the second author and colleagues, at Mt. Taibaishan in Shaanxi Province, has led us to reexamine the available material.We conclude that there are at least two species of Ectatosticta, that the specimens from Mt. Taibaishan and Inkiaphou in Shaanxi Province belong to E. davidi, and that the specimens from Qinghai Province described and illustrated by Forster et al. (1987) and other modern authors belong instead to a diff erent species, here described as E. deltshevi.
Natural History.According to observations by the second author at Mt. Taibaishan, E. davidi occurs in stony debris in open, semi-open, and forest-covered habitats.One part of the elongate sheet-web (Fig. 5) is situated at the surface and connected to a stone or rock and surrounding vegetation.Th e apparently larger part of the web leads, as a narrow band, deep into the debris.Spiders cannot be seen or lured out of their retreat during the day.When it gets dark, the spiders sit close to the surface part of the web, ready to escape to their retreat.One male was found walking around, apparently searching for a female.Another male was observed during courtship, at the margin of a female's surface web; that male touched the web only with its fi rst pair of legs.Th e third male was taken in its own web.

Figure 6 .
Figure 6.Map of China, showing records of Ectatosticta.