Spirothelphusa Pretzmann 1965

Spirothelphusa Pretzmann 1965 Strengeria (Spirothelphusa) Pretzmann, 1965: 8 [part]. Pseudothelphusa (Ptychophallus) — Bott 1968: 42 [part]. Spirothelphusa — Smalley 1970: 103 (list), 105 (key).— Rodríguez & Smalley 1972: 74.— Pretzmann 1972: 108.— Pretzmann 1974: 297.— Rodriguez 1982: 89.— Villalobos-Hiriart 2005: 17, 21, 22, 23 (tabla 2), 24, 39, 85, 88, 89, 183, 361 (Apéndice 1), 375 (anexo 1).— Villalobos-Hiriart et al. 1993: 286 (list).—Villalobos Hiriart & Álvarez 2008: 248 (tabla 1), 251, 297 (list).— Ng et al. 2008: 177 (list).— Villalobos & Alvarez 2010: 465, 471.— Alvarez & Villalobos 2016: 243.— Ojeda-Escoto 2017: 8, 11 (tabla 1.1), 13, 15, 16, 26 (fig. 1.12), 27, 38, 41 (tabla 2.2), 43, 90-91 (apéndice 2), 95 (apéndice 3).— Villalobos-Hiriart et al. 2019: 156 (table 1).— Álvarez et al. 2020: 12 (table 4), 19–21, 23–24 (key), supplementary material (table 1).— Moreno-Juárez et al. 2022b: 25 (fig. 1).— Moreno-Juárez et al. 2023: 2. Pseudothelphusa (Spirothelphusa) — Pretzmann 1971: 22. Diagnosis. Carapace with dorsal surface slightly convex, smooth; cervical and mid frontal grooves moderately deep, noticeable; frontal portion regularly curved downwards to form vertical front, superior border not well marked, smooth; lateral margin thin, serrated with small granules. Orbits with small, triangular, internal tooth, on inferior portion, triangular, low; orbital hiatus open. Exopod of third maxilliped subequal in length to lateral border of ischium (0.8 × length). G1 twisted, somewhat sturdy, distal third twisted towards median axis of sternal surface of the body; caudolateral border of principal axis with lateral lobe as wide subcircular laminar plate, with slightly irregular, sharp edge; caudo-marginal projection ending apically in prominent oval lobe, which wraps around gonopod cephalic surface. In mesial view, marginal plate and caudal surface fused on distal third to form caudo-marginal projection, twisted mesially, ending apically in prominent oval lobe that extend distally beyond apical cavity, borders serrated with small spinules (Fig. 7A). Lateral plate extending transversly along apical cavity, distal crest with spinules and setae, internal surface with scattered spinules. Mesial process hidden by distal lobe of caudo-marginal projection. Marginal plate and marginal suture straight, perceptible on proximal two thirds of principal axis, fusing with caudo-marginal projection on distal third. In cephalic view, principal axis straight with evident median notch below lateral lobe of caudolateral border; inner surface of caudo-marginal distal lobe, partially visible, cephalic and distal margins spinulated (Fig. 7B). Mesial process, as laminate triangular plate with smooth borders, acute apices, cephalad directed to overlap inner surface of caudo-marginal projection lobe, closing apical cavity, separated from the apical plate of lateral surface by a shallow notch. Lateral process with distal crest convex, spinulated. Accessory subapical spine slender, conical, acute. Lateral lobe on distal half of caudolateral border of principal axis entirely visible, surface with sparce granules, widely convex sharp edge. In lateral view, distal half of principal axis slightly inclined caudally; apical plate of lateral surface transversly ovoidal, cephalic end triangular, distal crest spinulated, caudal end rounded, surface with some granules and low protuberance (Fig. 7C). Mesial process just protruding from lower margin of apical lateral plate cephalic end. Accessory subapical spine slender, conical, acute. Lateral lobe on distal half of principal axis with surface granulated, margin slightly irregular, widely convex. In caudal view, principal axis distal half straight, median notch evident, caudal border broad, rounded (Fig. 7D). Caudo-marginal projection lobe oval shaped, overlying on distal portion of caudal border, marginally ornamented with spinules, surface smooth. Transversal lateral plate ovoid, marginally ornamented with spinules and short stout setae, internal surface with scattered spinules on central portion, cephalic end triangular, apices little projected, caudal portion rounded. Mesial process partially visible, hidden by lobe of caudo-marginal projection, triangular, superior margin with mid bulge, separated of cephalic end of transversal lateral plate by V-shaped notch. Lateral lobe of principal axis not completely visible, smooth caudal surface, moderately curved cephalically. In distal view, apical cavity narrow, widening towards cephalic portion; delimited by lobe of caudo-marginal projection, distal crest of lateral process, and mesial process, which is partially fused to lateral plate. Internal surface of lateral plate with spinules (Fig. 7E). Setae field not perceptible. Spermatic channel opening slit-like, in caudal position, bordered by a short and vertical median crest. Type species. Pseudothelphusa verticalis Rathbun, 1893, designated by Bott (1968). Species included. Spirothelphusa verticalis (Rathbun, 1893). Distribution. This monotypic genus is known from Tehuantepec region, Oaxaca, Mexico, with specimens collected by Dr. Spear, 4 males, 5 females, without a precise locality and date of collect, are deposited in the U. S. National Museum of Natural History (USNM 2537). It can be applied both to the entire isthmus of this name and only to the town of Santo Domingo Tehuantepec located near the Pacific coast of the state of Oaxaca (Rodríguez & Smalley 1972). New records extend the presence of S. verticalis to the northwest of the state of Chiapas in the municipalities of Ocozocoautla de Espinosa and Jiquipilas.