Texella

Texella tuberculata, photographed by Jean Krejca.
Belongs within: Phalangodidae.

Texella is a genus of harvestmen found in the southern and western US, with several species found in cave habitats.

Characters (from Ubick & Briggs 1992): Total body length 1.2-2.7; scute length 0.8-1.7. Body color from yellowish white to brownish orange, appendages relatively paler. Body cuticle with uniform layer of hemispherical to ovoid microtubercles, appearing smooth (microtubercles about 5 µm in diameter) to rugose (about 10 µm) at normal magnifications, and scattered patches of larger tubercles (from about 20 µm), which may be elongate, scale-like, and setiferous; setation light to moderate, most pronounced on the abdomen. Scute with eye mound at anterior margin; thoracic region set off dorsally by transverse grooves and laterally (at insertion of leg III) by pronounced constriction; abdominal region typically with five transverse rows of coarse tubercles representing fused tergites I-V. Eye mound roughly conical, reduced in troglomorphic species, rugosity smooth to coarse; eyes well developed, reduced, or absent. Anterior tubercles present or absent. Ozopores well developed, on anteriolateral margin, with distinct posterior channel. Tergites VI-VIII free, typically with median, transverse rows of coarse tubercles interspersed with short setae. Venter textured similarly as scute but more densely setose. Coxae with coarse tuberculation typically on ventral surfaces, retrolaterally on coxae II, and prolaterally on coxae IV; endites mesoapically situated on palpal coxae, coxae I, and coxae II; anteriorly directed spur on ventral surface of palpal coxae. Genital operculum between coxae IV, roughly semicircular, may be armed apically with 1-2 pairs of spines or tubercles. Large to small conical, cuticular outgrowth (=postopercular process) immediately behind genital operculum present in males of most species. Sternites typically with transverse rows of tubercles; sternite I with spiracle near distal part of coxa IV; stemites II-V free; sternites VI-VII fused. Anal operculum coarsely tuberculate and setose.

Chelicerae with smooth cuticle, basal segment with dorsoapical swelling, apical segments dorsally setose. Palpi with smooth cuticle of appressed scales, apically setose, typically robust but conspicuously attenuated in highly troglomorphic species; megaspine number and distribution: trochanter: 1-2 ventral (small); femur: 3 ecto(ventro)basal, 1-2 mesoapical; patella: 1 ectal, 1-2 mesal; tibia: 2 ectal, 2-3 mesal; tarsus: 2 ectal, 2 mesal. Legs with cuticle of apically rebordered scales giving honeycomb appearance; calcanei and tarsi smooth; lightly to moderately setose; leg II longest, leg formula (longest to shortest) II-IV-I-III; leg II length/scute length = 2-15; tarsal counts typically 3-5-4-5, 3-5-5-5, and 3-5-5-6, but up to 4-8-6-8 in highly troglomorphic species; tarsal claws single on legs I and II, paired on legs III and IV; legs of juveniles with posterior claws on onychium and enclosing arolium. Trochanter IV with ventral tubercles (females, some males) or elongate process (=spur) (most males); spur generally slightly curved, ventrally with smooth knobs, apically bent or enlarged.

Penis without muscles, composed of basal sac, truncus, and apical glans. Ventral plate bifurcate; incision at least as wide as glans width; each prong with a rigid, cuticular, apical spine and movable setae; setae arranged in dorsal, lateral, and ventral series. Glans double folded, appearing sigmoid in lateral view, expansion along two axes of rotation: 1) junction of basal and middle segment and 2) junction of apical segment and stylus; basal segment typically with ventroapical extension (=basal knob); middle segment with a pair of distal lobes (parastylar lobes), occasionally with a pair of secondary parastylar lobes; stylus apical, may bear a pair of basolateral processes (stylar apophyses) and ventral carina. Ovipositor bent or straight; cuticle wrinkled, with longitudinal and transverse folds; microsculpturing of small, thin spines, serrations, or rounded tubercles, rarely smooth; apex with dorsoventral slit, typically with a pair of teeth; setal pattern: 4 pairs lateral, 1 pair ventral, subapical, and 2 pairs dorsal, subapical; subapical setae located in cuticular folds. Hyperexpanded ovipositor with four apical valves and a patch of small basolateral spines.

Texella Goodnight & Goodnight 1942 UB04
    |--*T. mulaiki Goodnight & Goodnight 1942 K03, UB04
    |--T. bifurcata (Briggs 1968) [=Sitalcina bifurcata] UB04
    |--T. bilobata Ubick & Briggs 1992 UB04
    |--T. brevidenta Ubick & Briggs 1992 UB04
    |--T. brevistyla Ubick & Briggs 1992 UB04
    |--T. cokendolpheri Ubick & Briggs 1992 UB04 [incl. T. watersi Ubick & Briggs 1992 (n. n.) K03]
    |--T. deserticola Ubick & Briggs 1992 UB04
    |--T. dimopercula Ubick & Briggs 2004 UB04
    |--T. diplospina Ubick & Briggs 1992 UB04
    |--T. elliotti Ubick & briggs 2004 UB04
    |--T. fendi Ubick & Briggs 1992 UB04
    |--T. grubbsi Ubick & Briggs 1992 UB04
    |--T. hardeni Ubick & Briggs 1992 UB04
    |--T. hartae Ubick & Briggs 2004 UB04
    |--T. hilgerensis Ubick & Briggs 2004 UB04
    |--T. homi Ubick & Briggs 1992 UB04
    |--T. jungi Ubick & Briggs 1992 UB04
    |--T. kokoweef Ubick & Briggs 1992 UB04
    |--T. longistyla Ubick & Briggs 1992 UB04
    |--T. reddelli Goodnight & Goodnight 1967 UB04
    |--T. renkesae Ubick & Briggs 1992 UB04
    |--T. reyesi Ubick & Briggs 1992 UB04
    |--T. shoshone Ubick & Briggs 1992 UB04
    |--T. spinoperca Ubick & Briggs 1992 UB04
    |--T. tuberculata Ubick & Briggs 2004 UB04
    |--T. wellbourni Ubick & Briggs 1992 UB04
    |--T. whitei Ubick & Briggs 2004 UB04
    `--T. youngensis Ubick & Briggs 2004 UB04

*Type species of generic name indicated

REFERENCES

[K03] Kury, A. B. 2003. Annotated catalogue of the Laniatores of the New World (Arachnida, Opiliones). Revista Ibérica de Aracnología, volumen especial monográfico 1: 1-337.

Ubick, D., & T. S. Briggs. 1992. The harvestman family Phalangodidae. 3. Revision of Texella Goodnight and Goodnight (Opiliones: Laniatores). Texas Memorial Museum, Speleological Monographs 3: 155-240.

[UB04] Ubick, D., & T. S. Briggs. 2004. The harvestman family Phalangodidae. 5. New records and species of Texella Goodnight and Goodnight (Opiliones: Laniatores). Texas Memorial Museum, Speleological Monographs 6: 101-141.