52 BULLETIN 181, UNITED STATES NATIONAL MUSEUM 



ADEL0P03IA OCCIDENTALE (Guppy) 



Plate 40, Figube 6 



1872. Diplommatina Imttoni occidentalis Guppt, Proc. Assoc. Trinidad, vol. 2, p. 24. 

 1884. Diplommatina occidentale Godwin-Austen, Land and Freshwater Mollusca 



of India, vol. 1, pi. 45, fig. 8. 

 1886. Diplommatina occidentalis Godwin-Austen, ibid., p. 173. 

 1893. Diplomatina huttoni occidentale Guppy, Journ. Conch., vol. 7, p. 226. 

 1898. Palaina {Cylindropalaina) occidentalis Kobelt and Mollendoeff, Nachrbl. 



deutscheu malak. Ges., vol. 30, p. 133. 

 1902. Adelopoma occidentale Kobelt, Das Tierreich, vol. 16, p. 480. 



Shell minute, sinistral, thin, translucent, alabaster white, except the 

 nuclear turns, which are buff. Nuclear whorls 1.5, inflated, strongly 

 rounded, smooth. Post nuclear whorls inflated, strongly rounded, 

 marked by slender, lamellose, scalariform, decidedly protractively 

 slanting axial ribs, of which 27 occur on the first and second and 33 on 

 the last whorl. The spaces separating the axial ribs are four or five 

 times as wide as the ribs, and are covered by exceedingly fine, micro- 

 scopic spiral striations. Suture very strongly constricted. Base in- 

 flated, very strongly rounded, with a narrow umbilical chink, marked 

 by the continuation of the axial ribs. Aperture irregularly obliquely 

 oval; peristome double, the inner exserted; the outer narrowly ex- 

 panded. Operculum typically adelopomid. 



The specimen figured is one of nine, U.S.N.M. No. 203654, received 

 from Bland and comes from Trinidad. It has 6 whorls and meas- 

 ures: Height, 2.3 mm.; diameter, 1.2 mm. 



U.S.N.M. No. 98734 contains six specimens from the same source, 

 while U.S.N.M, No. 516033 contains seven specimens received from 

 Dr. George Clapp. 



This species differs from A. costaricense in being a little stouter 

 and having more axial ribs, which also are of uniform expansion 

 from the summit to the periphery. 



Subfamily Amphicyclotinae Kobelt and Moliendorff 

 Cyclophorids of helicoid outline with chondroid operculum. 



KEY TO THE WEST INDIAN GENERA OF THE SUBFAMILY AMPHICYCLOTINAE 



Operculum with fimbriations Cyclohaitia 



Operculum without fimbriation.s Amphicyclotulus 



CYCLOHAITIA, new genus 



Small amphicyclotine shells with strong spiral cords on spire and 

 base. Operculum multispiral, chondroid, with the outer edge of 



