Fig. 3 in New Taxa And Cryptic Species Of Neotropical Snakes (Xenodontinae), With Commentary On Hemipenes As Generic And Specific Characters

Fig. 3. Hemipenes of Eutrachelophis bassleri, new species. The distal nude section is greatly distensible, becoming hemispherical on eversion. Because of differential tissue expansion, the close-lying branches of the sulcus spermaticus diverge and acquire a centrifugal orientation, entering onto the nude dome from nearly opposite sides of the everted organ. A. Uneverted left hemipenis of AMNH R-55786 (paratype), opened by midventral incision. B. Everted right hemipenis in sulcate view, AMNH R-25193 (paratype; depiction of the manually everted organ). C. Same organ as in B, in asulcate view. D. Distal half of everted hemipenis showing appearance of the maximally inflated, mostly nude dome, from left to right: asulcate side, apex, and sulcate side. Left organ of TCWC 41424, paratype. (This organ previously had been manually turned inside out, but, because the base had been badly damaged, only the distal half was tied off and injected with petroleum jelly in an attempt to determine maximum inflation). Abbreviations: Folds, expansion folds; Mus, major retractor muscle; ND, nude dome; SB, a branch of the sulcus spermaticus; SS, sulcus spermaticus (proximal to bifurcation); Spic, densely spiculate area below and around base of nude dome; SpLg, large lateral and basal spines; SpSm, small spines on sulcate and asulcate faces.