14 LIST OF CYCLOPHORID^. 



b. Operculum horny, thin without any external calcareous layer. 

 Shell conical or depressed. Last whorl rounded, without any 

 groove or ridge round the front of the axis. 



4. AULOPOMA. 



Operculum horny, with many whorls ; outer edge larger than the 

 aperture, and reflexed over the peristome of the shell. — Shell 

 turbinate, depressed, or subdiscoidal, the last whorl anteriorly 

 open ; peristome free, straight, continuous, immersed in the cir- 

 cular groove of the operculum. 



Aulopoma Troschel in Menke und Pfeiffer, Z.f Malak. 1847, 43. ; 

 Pfeiffer in Menke und Pfeiffer, Z.f. Malak. 1847. 



1. Aulopoma cornu venatorium. 



Cyclostoma cornu venatorium Sow. Thes. Conch, i. 107. n. 48. 



t. 24. f. 41— 42.; Pfeiffer, Kuster, Chemn. Conch. Cab. i. 19. 



t. 22. f. 1—3. 

 Aulopoma cornu venatorium Pfeiffer, 1. c. 111. n. 1. 



a. Ceylon. 

 b—f Ceylon. 



g — I. Ceylon. Presented by H. L. Layard, Esq. 

 m — q. Ceylon. Var. small. Presented by H. L. Layard, Esq. 

 r — 5. Ceylon. With operculum. Presented by H. L. Layard, 

 Esq. 



2. Aulopoma helicinum. 



Cyclost. helicinum? Pfeiffer, Kuster, Chemn. Conch. Cab. i. 19. 



t. 22. f. 4, 5. 

 A.? helicinum Pfeiffer, 1. c. 111. n. 2. 



Bab. ? 



3. Aulopoma Itierii. 



A. Itierii Guer.; Pfeiffer, I.e. 111. n. 3. 



Hob. ? 



4. Aulopoma Hopfmeisteri. 



A. Hoflmeisteri Trosch.; Pfeiffer, I.e. 111. n. 4. 

 Hob. ? 



5. MYXOSTOMA. 



Operculum thick, lamellar, subcartilaginous, many-whorled. — 

 Shell widely umbilicated, depressed. Peristome double ; the 

 internal continuous, entire ; the external reflexed, with a beak 

 behind closely pressed to the last whorl. 



