Eucteniza Ausserer, 1875

Bond, Jason E. & Godwin, Rebecca L., 2013, Taxonomic revision of the Trapdoor spider genus Eucteniza Ausserer (Araneae, Mygalomorphae, Euctenizidae), ZooKeys 356, pp. 31-67 : 36-39

Genus Eucteniza Ausserer, 1875 Figs 1-7

Eucteniza Ausserer, 1875: 149 (type species by monotypy Eucteniza mexicana juvenile holotype from Mexico, deposited in BMNH, examined). - E. Simon 1892: 110. - F.O.P.-Cambridge 1897: 12. - Bond and Opell 2002.

Flavila O.P.-Cambridge, 1895: 156 (type species by monotypy Flavila relatus O.P.-Cambridge, male holotype from Mexico, Amula in Guerrero, deposited in the BMNH, examined). - synonymized by F.O.P.-Cambridge 1897: 13.

Enrico O.P.-Cambridge, 1895: 157 (type species by monotypy Enrico mexicanus juvenile holotype from Mexico, Atoyac, Veracruz, deposited in BMNH, examined). - F.O.P.-Cambridge 1897: 12. - E. Simon 1903: 899. - synonymized by Bond and Opell 2002.

Astrosoga Chamberlin, 1940: 5 (type species by monotypy Astrosoga rex male holotype from Kingsville, Texas, deposited in AMNH, examined). - Chamberlin and Ivie 1945: 556. - synonymized by Bond and Opell 2002.

Diagnosis.

Eucteniza males can be recognized by the presence of 1-2 mid-ventral megaspines on the tibia of both legs I and II (Figs 8-10). Such mating clasper spination configuration is similar to that of Neoapachella males for leg I but are absent on leg II. Females can be distinguished from all other euctenizid genera by having what appears to be a bi-dentate cheliceral furrow and a rastellum positioned on a moderate to high rastellar mound, whereas other genera have a single row of promarginal teeth and a small patch of denticles and lack a distinct rastellar mound. Additional Eucteniza autapomorphies include a patella IV spine patch and a weakly sclerotized posterior carapace margin.

General description.

Small to large sized trapdoor spiders. Cephalothorax longer than wide, sloping posteriorly, lacking pubescence in most species (Fig. 2). Posterior third of carapace very lightly sclerotized (Figs 2, 23, 24). Thoracic groove intermediate to wide, procurved (Fig. 2) and deep. Eyes not on a tubercle (Fig. 3). AME, PME subequal diameter. Posterior eye row slightly recurved, anterior eye row slightly porcurved (Fig. 2). Caput moderately high (Fig. 3). Carapace of ethanol preserved specimens appears most often reddish-brown, sometimes lighter. The coloration of living spiders tends to be a darker brown, however there is considerable variation in the intensity of coloration. Male coloration in most specimens is dark reddish-brown. Abdominal coloration light to dark brown, sometimes with dark mid dorsal blotch.

Sternum wider posteriorly, tapering anteriorly (Fig. 4). Posterior sigilla large and positioned mid-posteriorly nearly contiguous. Anterior margin of sigilla lacks rounded margin. Palpal endites longer than wide with numerous cuspules (Fig. 4). Labium wider than long, with numerous cuspules (Fig. 4). Chelicerae dark brown. Rastellum consists of numerous spines borne on a distinctive mound. Fangs of intermediate length and thickness. Cheliceral promargin with row of very large teeth; retromargin row comprises distinct row of large teeth interspersed with denticles.

Apical PLS article short, digitiform. Spinnerets mostly with pumpkiniform spigots with several articulated spigots interspersed on apical and median articles of PLS and the PMS ( Bond and Opell 2002, fig. 3E). Two to three large, articulated spigots on apical most aspect of the PLS. PMS article robust. See Bond and Opell (2002) for more detailed descriptions of spigot types.

Anterior leg articles slender relative to posterior. Tarsi short and robust (Figs 5-6). Female scopulae long, dense, asymmetrical, extending full length of tarsus, metatarsus and half length of tibia on anterior legs; posterior legs lack distinct scopulae. Male tarsi I and II with short sparse scopulae that are restricted to the ventral surface. Basal palpal tooth and STC I - IV basal tooth elongate and bifid. STC IV with 5 or more teeth. Female anterior legs with very few ventral spines (Fig. 5). Prolateral surface of female patella III and IV covered in numerous thick short spines (Fig. 6). Preening comb on metatarsus IV absent; metatarsus, tarsus IV with ventral spines (Fig. 7). Tarsal trichobothria arranged in a wide band with interspersed setae. Spermathecae generally comprise a simple unbranched bulb that lacks an elongate base.

Male mating clasper morphology is distinctive. Tibia legs I & II swollen mid-ventrally in most species, bearing 1-2 large spines; prolateral aspect with a small to large patch of smaller, thickened, short spines. Metatarsus of leg I lacks excavation and spur. Palpal bulb simple, with spherical base, planar distally near origin of embolus. Palpal cymbium lacks dorsal spines (Fig. 11).

Distribution.

Distributed primarily throughout central Mexico and Baja California (Fig. 1) with an extension northward into Texas (United States).

Key to males

Note: as discussed by Bond (2012) keys to many mygalomorph taxa are sometimes far from optimal and thus one should not rely too heavily on species determinations using this key. Instead, knowledge of where specimen was collected and comparison to description and illustrations will likely prove more useful.

Nomen dubium

Eucteniza atoyacensis Bond & Opell, 2002. Replacement name: Enrico mexicanus (O.P.-Cambridge, 1895) = Eucteniza atoyacensis . Holotype specimen is a juvenile and thus no known specimens or species can be unambiguously attributed to this name at this time.