THE CYCILOPHORID LAND MOIiLIJlSES OF AMEKTCA 247 



The type, U.S.N.M. No, 104451, comes from Balsas, Peru. It was 

 in the Lea collection. It has 4.3 whorls and measures: Height, 14.2 

 mm. ; greater diameter, 27.5 mm. ; lesser diameter, 19.2 mm. Height 

 of aperture, 10.7 mm.; diameter, 12.3 mm. 



The obsolete ribbing immediately below the periphery distin- 

 guishes this species from A. (A.) peruense and A. (A). Nancheti- 

 anum (Moricand). 



APEROSTOMA (APEROSTOMA) VENEZUELENSE, new species 



Plate 35, Figukes 20-22 



Shell very depressed-helicoid, thin, covered with an olivaceous 

 periostracum, which is streaked and blotched with darker olive. 

 There is a faint light zone immediately above the periphery and a 

 broad weak brown band immediately below it. A second slender 

 spiral line lies a little posterior to the middle of the base. The rest 

 of the base is a little paler than the upper surface; interior of 

 aperture bluish white. The nucleus consists of 2 small, well-rounded, 

 smooth turns. The postnuclear whorls are strongly rounded, the 

 last one slightly deflected at its extremity. They are marked by 

 obsolete axial riblets, which become quite irregular on the last whorl, 

 where also some slight malleations are present. The last whorl is 

 slightly flattened a little below the summit and the suture is deeply 

 narrowly channeled. Periphery obsoletely angulated. Base openly 

 broadly umbilicated, inflated, and marked by the same type of sculp- 

 ture as that which characterizes the upper surface of the last whorl, 

 except that on the umbilical wall the riblets become a little more 

 distant. Aperture broadly oval, with a slight angulation at the 

 posterior angle; peristome simple; the outer lip thin; the inner only 

 slightly thickened. The parietal wall is covered by a moderately 

 thick callus, which renders the peritreme complete. 



The type, U.S.N.M. No. 307429, was collected by Cuming in Vene- 

 zuela. It has 4.2 whorls and measures: Height, 14.7 mm.; greater 

 diameter, 29.7 mm.; lesser diameter, 21 mm. Height of aperture, 

 11.3 mm. ; diameter, 12.8 mm. 



This species agrees with A. (A.) depressv/m (Da Costa) in having 

 the axial ribs obsolete; it differs from that, however, in having the 

 whorls strongly downward flexed near the suture and more rounded. 



APEROSTOMA (APEROSTOMA) DEPRESSUM (Da Costa) 



PiATE 35, Figures 14-16 



1906. Neocyclotus depressiis Da Costa, Proc. Malac. Soc. London, vol. 7, p. 9, 



pi. 1, figs. 14-16. 

 3923, Poteria (Neocyclotus) depressus H. B. Bakee, Occ. Pap. Mus. Zool. Univ. 



Michigan, No. 137, p. 42. 



