CYCLOPHORID&. 191 
Cyclostoma interrupta, Delessert, Recueil, t. 29, £. 2; Chenu, Til. 
Conch. t. 1, f. 2. 
Cyclostoma ambiguum, Pfr. Jc. n. 196, p. 178, t. 29, f. 7-9. (From 
Deless.) 
Choanopoma ambiguum, Gray, Cat. Cycl. p. 50, n. 9. 
Cistula? ambigua, Pfr. Consp. n. 400; Pnewm. Mon. p. 271. 
Locality unknown. 
22. CistuLA? RIGIDULA. 
Shell turreted, for the most part truncated, sculptured with 
minute lamellar ribs, coarse, horn-coloured-grayish, marked 
with 4-5 interrupted rufous bands; spire conic-turreted, with 
the apex rather smooth; whorls 73, convex, the last detached, 
more or less protracted downwards; suture deep; aperture ob- 
long, of the same colour within; peristome double; outer edge 
lamellar, spreading, produced above on the right side into a 
concave angle. Length 12, breadth 5 mill. 
Cyclostoma rigidulum, Morelet, Testac. Noviss. ii. p. 18, n. 126. 
Cistula? rigidula, Pfr. don. Pneum. p. 418, n. 445a. 
Hab. Guatemala, Vera Paz. 
23. CistTULA? BILABIATA. 
Shell scarcely perforate, turreted, rather thin, trellised with raised 
spiral lines and more crowded longitudinal strie, faintly silk- 
shining, fuscous violaceous; spire regularly tapering, not trun- 
cate; suture minutely crenulate; whorls 6, moderately convex, 
last narrower, detached anteriorly; aperture perpendicular, 
roundish-ovate; peristome double; inner edge shortly promi- 
nent; outer edge spreading rather equally and horizontally, 
angularly dilated above. Operculum? Length 13, breadth 6 
mill. 
Cyclostoma bilabiata, Orbigny, Moll. Cub. i. p. 258, t. 22, f. 3, 5. (2) 
Cyclostoma Dorbignyanum, Petit, Journ. Conch. 1850, i. p. 46. 
Cyclostoma bilabiatum, Pfr. Jc. n. 322, t. 43, f. 31, 32. 
Choanopoma? bilabiatum, Gray, Cat. Cycl. p. 52, n. 22. 
Cistula? bilabiata, Pfr. Consp. n. 401; Pneum. Mon. p. 271. 
Hab. Cuba. 
24, CisTULA GRATELOUPI. 
Shell perforate, oblong, pupiform, truncate, rather thin, sculp- 
tured with crowded spiral furrows, and crowded, not interrupted, 
longitudinal ribs, diaphanous, somewhat shining, horn-coloured- 
whitish, painted with chestnut-coloured bands, which are in- 
terrupted by streaks; spire little lessened towards the summit, 
