CYCLOPHORID &. $l 
Pterocyclos Cumingi, Pfr. in Proc. Z. S. 1851; and Z. f. If, 1851, 
p. 5; Je. t. 31, f. 6-8; Consp. n. 55; Pneum. Mon. p. 48. 
Hab. Ceylon. 
13. PreRocycLos BILABIATUS. 
Shell depressed, nearly discoidal, slightly striate, whitish, with 
angular chestnut-coloured stripes; spire scarcely raised, with 
the apex rather blunt, blackish ; whorls 5-53, moderately con- 
vex, gradually increasing, the last one cylindrical with a brown 
band at the periphery; umbilicus broad ; aperture oblique, cir- 
cular; peristome double; inner edge nearly continued, straight, 
deeply notched above, outer edge vaulted into the shape of a 
eap near the penult whorl, with the right and basal margins 
deeply sinuous and undulated. Opere. typical. Height 83, 
greatest breadth 20, least br. 17 mill. 
Pterocyclos bilabiatus, Bens. in Zool. Journ. v. p. 462; Sourn. 
As. Soc. v. p. 358; Pfr. in Z. f. M. 1847, p. 111, 1851, p. 4; Lc. 
p. 193, t. 24, f. 11-14; Consp. n. 56; Gray, Cat. Cycl p. 13, 
n.6; Pfr. Pneum. Mon. p. 49. 
Cyclostoma bilabiatum, Sow. Thes. n. 57, p. 110, t. 25, f. 81, 82; 
Petit, in Journ. Conch. i. p. 43. 
Hab. India, Salem, near Madras (Heath, Sowerby). 
14, Prrrocyctos Buanpt. 
Shell orbiculate-depressed, whitish, with radiating, undulated, 
brownish-orange-coloured stripes, and one darker band at the 
periphery ; whorls 43, increasing rapidly, the last one suddenly 
dilated into a broad wing anteriorly ; umbilicus very broad ; 
aperture oblique; peristome rather duplicate; inner edge 
thickened, disjoined, and sinuous above; outer edge broadly 
expanded above, with a wing, which is disjoined, angulate 
anteriorly, descending, produced over the penult whorl, showing 
a sinus posteriorly. Greatest breadth 29, least br. 23 mill. 
(Bens.) 
Pterocyclos Blandi, Bens. in Ann. & Mag. viii. 1851, Aug. t. 5, 
f.1; Pfr. Consp. n. 58; Pneum. Mon. p. 49. 
Hab. Island of Pulo Susson, near Pulo Penang. 
15. Przrocycios ? SPIRACELLUM. 
Shell suborbiculate, planorboid ; spire depressed, pale ; whorls 4, 
rounded, transversely striate, the last one inflate above, then 
attenuated, and as it were strangulated, with a vaulted varix 
near the aperture, which is circular; peristome double ; inner 
edge emarginate posteriorly; outer edge reflected, terminated 
posteriorly into a channel ; suture distinct ; last whorl bearing 
a tubular spiraculum near the aperture ; umbilicus open, show- 
