TBDB CTCUOPHORrD LAND MOLLUSES OF AMERHCIA 227 



The small size will easily distinguish this from the other members 

 except A. (A.) inconspicimm (Sowerby), which is even smaller. 



APEROSTOMA (APEROSTOMA) SIMILE, new species 

 Plate 31, Figxtbes 13-15 



Shell helicoid, small, covered with a horn-colored periostracum, 

 which on the last whorl becomes decidedly olivaceous. There is a 

 broad, pale, darker band on the posterior half of the base. The 

 nucleus consists of about 1.5 smooth turns. The postnuclear whorls 

 are marked by retractively slanting incremental lines, which become 

 increasingly closer spaced as the shell advances in age. In addition 

 to these incremental lines the whorls are marked by rugosities sepa- 

 rated by more or less strongly impressed scratches. Suture well 

 impressed. Periphery feebly angulated. Base somewhat inflated, 

 rather openly umbilicated, well rounded, and marked by the con- 

 tinuation of the incremental lines, which extend upon the umbilical 

 wall, and mere indications of rugosities. Aperture subcircular, ob- 

 lique; peristome simple, the outer thin; the inner somewhat thick- 

 ened, more so on the parietal wall. Operculum typically aperostomid. 



The type, U.S.N.M. No. 535989, was received from Sowerby & 

 Fulton with the locality "Bogota" (Colombia). It has 4.1 whorls 

 and measures: Height, 13 mm.; greater diameter, 19.3 mm.; lesser 

 diameter, 15 mm. 



U.S.N.M. No. 307398 contains another specimen from the same 

 locality, while U.S.N.M. No. 307400 contains a specimen bearing the 

 label "New Grenada." 



In size and general coloration this species agrees fairly well with 

 A. (A.) hogotense (Pfeiffer). The less developed rugose sculpture 

 and more scattered nodulation will readily distinguish it from this. 



APEROSTOMA (APEROSTOMA) INCONSPICUUM (Sowerby) 



PI.ATE 31, Figures 10-12 



1843. Cyclostoma inconspicuum Sowebbt, Thesaurus Conchyliorum, vol. 1, p. 



109, pi. 24, figs. 73-74. 

 1912. Neocyclotus papayanus fasciata Kobelt (pars), Martini-Chemnitz Con- 



chylien Cabinet, vol. 1, sect. 19, pt. 3, p. 901. 

 1923. Poteria {Neocyclotus) incotispicuum, H. B. Baker, Occ. Pap. Mus. Zool. 



Univ. Michigan, No. 137, p. 44. 



Shell small, helicoid, covered by a pale-brown periostracum. There 

 is a narrow pale chestnut zone immediately below the periphery, 

 and above this a white band of about the same width. The posterior 

 half of the base below the dark band is olivaceous, gradually paling 

 toward the umbilicus. The nucleus consists of about 1.5 small, in- 

 flated, well-rounded, smooth turns. The early postnuclear whorls 



