270 BULLETIN 181, UNITEiD STATES NATI0!N1AX. MUSEUM 



aperostoma (cyclohidalgoa) translucidum major (h. b. baker) 



Plate 30, Figures 13-15 



1923. Poteria {Neooyclotus) translucida major H. B. Bakeb, Occ. Pap. Mus. 

 Zool. Univ. Michigan, No. 137, pp. 33, 34, pi. 5, fig. H. 



Shell large, helicoid, well elevated, covered by a thin, yellowish 

 horn-colored periostracum. The nucleus consists of 2 small, well- 

 rounded smooth turns. The postnuclear whorls are strongly 

 rounded; the last one appressed at the summit and marked by re- 

 tractively curved axial riblets, which become irregular on the last 

 half of the last turn. Suture strongly impressed. Periphery in- 

 flated, well rounded. Base narrowly umbilicated, inflated, well 

 rounded, and marked by the weak continuation of the axial sculp- 

 ture, which extends over the umbilical wall. Aperture large, 

 almost circular, with a slight angulation at the posterior angle; 

 peristome simple, the outer lip sharp; inner lip slightly thickened. 

 The parietal wall is covered by a thick callus, which renders the 

 peritreme complete. 



The specimen described and figured is one of three, U.S.N.M. No. 

 360680, collected by H. Pittier near Barquisimeto, Lara, Venezuela. 

 It has 4.8 whorls and measures : Height, 22.9 mm. ; greater diameter, 

 27.2 mm.; lesser diameter, 20.3 mm. Height of aperture, 13 mm.; 

 diameter, 13.7 mm. 



The National Museum collections contain additional specimens: 

 No. 362142, two specimens, also collected by Pittier at Puerto La 

 Cruz, Venezuela ; No. 307500, two specimens, collected by MacMurray 

 at the Penal Settlement, Essequibo Province, British Guiana; 

 U.S.N.M. No. 428119, one specimen, collected by J. P. Morrison at 

 Kamaria, British Guiana. 



The large size will readily distinguish this from the other sub- 

 species of translucidum. It is possible that when more material has 

 been received from the various stations included in the wide range 

 that we are here assigning to this subspecies it will be necessary to 

 divide it further, but we have not now enough to make this desirable. 



APEROSTOMA (CYCLOHmALGOA) TRANSLUCIDUM BEJUMENSE (H. B. Baker) 



Plate 30, Figure:s 4r-6 



1923. Poteria {Neocyclotus) translucida hejumensis H. B. Baker, Occ. Pap. 

 Mus. Zool. Univ. Micliigan, No. 137, pp. 33, 34, pi. 5, figs. D, E, F, G. 



Shell helicoid, strongly elevated, covered with an olivaceous horn- 

 colored periostracum, which is a little darker on the early turns than on 

 the last; interior of aperture bluish white. The denuded tip is red- 

 dish. The nucleus consists of 2 well rounded, smooth turns. The 

 postnuclear whorls are inflated, strongly rounded, and marked by 



