THE CYCIiOPHORID LAND MOLLUSKS OF AMERTCIA 271 



rather strong, retractively curved axial riblets, which are about as 

 wide as the spaces that separate them, and which become intensified 

 toward the last part of the last turn. Suture strongly impressed. 

 Periphery well rounded. Base narrowly umbilicated, inflated, strongly 

 rounded, and marked by the continuation of the wavy axial riblets, 

 which extend also over the umbilical wall. Aperture subcircular, pro- 

 duced at the posterior angle into a rather strong auriculation ; peristome 

 simple, outer lip thin ; inner thickened. The parietal wall is covered 

 by a rather thick callus, which renders the peritreme complete. Oper- 

 culum typically aperostomid, showing 5 whorls. 



Acad. Nat. Sci. Philadelphia No. 140913 contains two paratypes, one 

 of which we have described and figured. They come from Banco 

 Largo, Bejuma, Venezuela. The specimen described and figured has 

 4.5 whorls and measures : Height, 15.8 mm. ; greater diameter, 18.8 mm. ; 

 lesser diameter, 13.9 mm. Height of aperture, 9.1 mm.; diameter, 

 9.2 mm. 



This subspecies is nearest related to A. {C.) translv^idvm trinitense 

 (Guppy), from which it is easily distinguished by its coarser axial 

 sculpture. 



APEROSTOMA (CYCLOHmALGOA) TRANSLUCIDXJM TRINITENSE (Guppy) 



Plate 30, Figubes 1&-18 



1864. Cyclotus trinitemis Guppy, Ann. Mag. Nat. Hist., ser. 3, vol. 14, p. 245. 

 1866. Cyclotus translucidus Guppy, Ann. Mag. Nat. Hist., ser. 3, vol. 17, pp. 45, 46. 

 1890. Neocyclotus translucidus trinitensis Ckosse, Journ. Conchyl., vol. 38, p. 54. 

 1023. Poteria {Neocyclotus) translucida trinitensis H. B. Bakeb, Occ. Pap. Mus. 

 Zool. Univ. Michigan No. 137, pp. 31, 33, pi. 5, figs. B, C. 



Shell helicoid, rather elevated, the early whorls rose-red, the last 

 one yellowish horn colored; interior of aperture bluish white. The 

 nucleus consists of 2 well-rounded smooth turns. The postnuclear 

 whorls are somewhat inflated, well rounded, and marked on the pe- 

 nultimate whorl by very fine axial riblets; on the last whorl these be- 

 come a little coarser, and on the last portion of the last turn evanescent 

 and irregular. Below the appressed summit the last whorl is marked 

 by some oblique scratches. Suture strongly impressed. Periphery 

 strongly arched. Base narrowly umbilicated, inflated, strongly 

 rounded, and marked by the continuation of the axial ribs, which ex- 

 tend over the umbilical wall. Aperture circular, protracted into a 

 triangular auricle at the posterior angle. Peristome simple; outer lip 

 thin; inner lip slightly thickened. The parietal wall is covered by a 

 callus, which renders the peritreme complete. The operculum is typi- 

 cally aperostomid and shows 5 whorls. 



The specimen described and figured is one of three, Acad. Nat. Sci. 

 Philadelphia No. 104631, collected by S. Brown at Cariaquita, Vene- 



