CYCLOPHORIDZ. 163 
Choanopoma Humphreyanum, Gray, Cat. Cyel. p. 53, n. 25. 
Cyclostomus Humphreyanus, Pfr. Consp. nu. 340; Prnewm. Mon. 
p. 232. 
Hab, Jamaica. 
70. CycLOsTOMUS ALBUS. B. M. 
Shell perforate, ovate-conic, with the apex slightly truncate, 
rather smooth, alabaster-white, faintly shining; suture simple; 
whorls remaining 4, convex, the last as long as the two pre- 
ceding ones joined; aperture perpendicular, obliquely ovate ; 
peristome double; inner edge scarcely produced; outer edge 
shortly expanded, with the margins united into an indistinct 
angle. Operculum like that of C. elegans. Length 18, breadth 
1035 mill. 
Cyclostoma album, Sow. Thes. n. 139, p. 141, t. 28, f. 154; Pfr. Ic. 
n. 44, p. 51, t. 6, £. 17-19. 
Cyclostomus albus, Gray, Cat. Cycl. p. 47, n.17; Pfr. Consp.n.341 ; 
Preum. Mon. p. 232. 
8. Smaller, thinner, brownish, with the apex blackish. 
Hab, Jamaica. 
71. CycLostomus CHEVALIERI. 
Shell ovate-conic, brown, darker at the summit, white along the 
suture, around the umbilicus, and with the peritreme white; 
also with several spiral series of dark brown dots, of which 
series two on the upper whorls and three on the last are most 
conspicuous; smooth and shining; spire rather convex, trun- 
cated with the loss of more than two whorls; about four whorls 
remaining, which are quite convex, with a moderately-depressed 
suture; aperture nearly circular; the inner peritreme slightly 
developed; outer peritreme smooth and widely expanded (espe- 
cially above and on the left side), well appressed to the penul- 
timate whorl; umbilicus very small. Operculum similar to that 
of C.album. Mean divergence about 45°; length 0.68, greatest 
breadth 0.48, least br. 0.35 inch. 
Cyclostoma Chevalieri, Adams, Contrib. to Conch. n. 9, p. 155. 
Cyclostomus Chevalieri, Pfr. Consp. n. 342; Pneum. Mon. p. 283. 
Hab. Samaica. 
§ 10. Shell not keeled, ovate-turreted, folded longitudinally. Peristome 
expanded, double. 
72. CYCLOSTOMUS THYSANORHAPHE. B. M. 
Shell perforate, oblong-conic, truncate, closely sculptured with 
longitudinal fold-like striee, silk-shining, whitish, marked with 
chestnut-coloured interrupted bands and streaks; whorls re- 
