Aucana, HUBER, 2000

HUBER, BERNHARD A., 2000, New World Pholcid Spiders (Araneae: Pholcidae): A Revision At Generic Level, Bulletin of the American Museum of Natural History 2000 (254), pp. 1-348 : 105-106

AUCANA , NEW GENUS

TYPE SPECIES: Aucana platnicki , new species.

ETYMOLOGY: The generic name is derived from the Incan word Auca , referring to the unconquered Indians living between the Maipó and Bío-Bío rivers in Chile. More recently the term describes Araucanian Indians living mostly in Argentina.

DIAGNOSIS: Tiny pholcids (total length 1.1 1.4 mm), with short legs, globular opisthosoma, eight eyes; distinguished from oth- er short-legged genera by the several small frontal apophyses on the male chelicerae (other South American ninetines have either one pair: Nerudia , Kambiwa , Guaranita , Enetea ; or none: Gertschiola , Galapa ), and the dorsal apophysis proximally on the simple procursus (figs. 403, 407, 411, 417, 426).

DESCRIPTION: Total length ~ 1.1 1.4 mm. Carapace without thoracic groove. Ocular area not or hardly elevated, with eight eyes, AME smallest; distance PME-ALE relatively small (~ 30 40% of PME diameter). Male clypeus unmodified. Male chelicerae with some small, cone-shaped apophyses frontally, with stridulatory ridges laterally. Male sternum without humps. Male palpal coxa without retrolateral apophysis, femur widened distally, procursus simple, usually with transparent lamellae distally, with dorsal apophysis or projection proximally; bulb large, variable in shape; tarsal organ exposed (examined: A. platnicki , n. sp.; kaala , n. sp.; figs. 85 87). Legs very short (leg 1 about 3 3.5 × body length; tibia 1 l/d: 15 17), leg formula usually 1423 (in A. kaala legs 1 and 4 subequal); legs without spines, without curved and vertical hairs; retrolateral trichobothrium of tibia 1 distal (at ~ 50 60%); tarsus with only ~ 5 8 pseudosegments. Opisthosoma globular, with darker spots dorsally. Male gonopore without epiandrous spigots (examined: A. platnicki : fig. 133; kaala ). ALS with piriform gland spigots (examined: A. platnicki , kaala ; figs. 156 157), other spinnerets typical for family.

Sexual dimorphism slight; epigynum extremely simple externally, internally with circular median structure (figs. 405, 409, 413; receptacle?).

MONOPHYLY: The species included share the dorsal projection on the procursus. The Chilean species are extremely similar overall, and very probably form a monophyletic group. The New Caledonian species is included tentatively. It has similar procursi and chelicerae, and further similarities that are otherwise rare among short-legged pholcids: the absence of epiandrous spigots and exposed tarsal organs.

GENERIC RELATIONSHIPS: The genus may be close to several other genera of short-legged pholcids with globular opisthosoma and stridulatory files on the male chelicerae, es- pecially with the North American genus Chisosa , which shares the exposed tarsal organ and the absence of epiandrous spigots. All other ninetine characters (short legs, distal retrolateral trichobothrium, carapace without thoracic indentation, small size) may be plesiomorphies.

SPECIFIC RELATIONSHIPS: The type species as well as A. ramirezi , n. sp., and A. petorca , n. sp., have very similar procursi and identical male chelicerae. A. paposo , n. sp., differs in several aspects (bulb, procursus a simple, ribbon-shaped structure). A. kaala shows more pronounced differences in procursus and bulb, and has additional apophyses proximally on the male chelicerae; it is assigned tentatively (see Monophyly above).

DISTRIBUTION: Known from Chile and New Caledonia.

COMPOSITION: The genus as construed here includes five named species, all of which are newly described below. Apart from that I have seen at least three further species from New Caledonia (in AMNH, QMB).