286 CYOLOSTOMID^. 



the whorls rapidly increasing, thickened along the canaliculated 

 suture and terminating in a tongue-like, narrow projection, 

 appressed to the circumference of the last whorl. C. Naticoides, 

 Recluz. Several species, East Africa. 



ROCHEBRiJNiA, Bourguiguat, 1882. (Dedicated to Dr. Roche- 

 brune, of the Museum, Paris.) Inner lip without umbilical 

 dilation, so that the umbilicus is open. G. Philippianum, Pfeiffer. 

 11 sp. East African region. 



lY. Cyclophorea. 



Operculum thin, corneous, multispiral. The animals of this 

 extensive group are found in the humid parts of tropical forests, 

 either concealed among the debris at the roots of trees, or in- 

 habiting the branches and foliage ; some, however, prefer dry 

 and arid situations, while others take up their abode in the 

 immediate vicinity of the sea. 



Cyclophorus, Montfort. 



Etym. — Gyclos^ circle, j^hore us, bearer. 



Distr. — 200 sp. Tropical, mundane. C. volvulus, Miill. 

 (Ixxvi, 92). 



Shell depressed, ojaenly umbilicated ; aperture circular ; peris- 

 tome continuous, straight or expanded ; epidermis thick. Oper- 

 culum horn}^, many-whorled. 



Animal with long, slender, pointed tentacles ; foot broadly 

 expanded, not grooved. 



MYXOSTOMA, Troschcl. Shell discoidal, widely umbilicated ; 

 peristome double, the internal margin continuous, external 

 margin reflected, and produced into a tongue-like form pos- 

 teriorly. G. Iroscheli, Benson (Ixxvi, 93). 



THEOBALDius, Nevill. Shell subdiscoidal, widelj' umbilicated ; 

 peritreme circular, thickened, not much reflected, continuous. 

 Asiatic. C. annulatiis, Nevill (Ixxvi, 94). 



SCABRINA, Blanford. Shell depressed, subdiscoidal, widely 

 umbilicated ; epidermis hispid ; whorls rounded ; aperture 

 circular, peristome thickened. Opercuhim thick, corneous, the 

 margins of the whorls lamellately elevated. Asiatic. G. calyx, 

 Benson (Ixxvi, 95). 



BUCKLEYiA, Higgins. Shell discoidal, widely umbilicated ; 

 with revolving carina, and deciduous epidermis ; aperture 

 circular, vertical, margin continuous, adnate, thin, acute. So. 

 America. G. Martinezi^liidalgo (1-k-s.vi, 9Q, 21). 



MiCRAULAX, Theobald. Proposed for planorboid species 

 uniting the Myxostoma type with the turbinate Lagocheilus. 



LAGOCHEiLUS, Blanford. Shell conoid-subturbinate, perforated, 

 thin; aperture round, with a narrow incision in the posterior 

 angle. Operculum thin. Animal with a glandular slit at the 



