286 CYCLOSTOMIDA. 
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. 
ROCHEBRUNIA, Bourguignat, 1882. (Dedicated to Dr. Roche- 
brune, of the Museum, Paris.) Inner lip without umbilical 
dilation, so that the umbilicus is open. C. Philippianum, Pfeiffer. 
11 sp. East African region. 
IV. Cyclophorea. 
Operculum thin, corneous, multispiral. The animals of this 
extensive group are found in the humid parts of tropical forests, 
either concealed among the débris 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. 
EHtym.— Cyclos, circle, phoreus, bearer. 
Distr—200 sp. Tropical, mundane. C. volvulus, Mull. 
(Ixxvi, 92). 
Shell depressed, openly umbilicated ; aperture circular; peris- 
tome continuous, straight or expanded; epidermis thick. Oper- 
culum horny, many-whorled. 
Animal with long, slender, pointed tentacles; foot broadly 
expanded, not grooved. 
Myxostoma, Troschel. Shell discoidal, widely umbilicated ; 
peristome double, the internal margin continuous, external 
margin reflected, and produced into a tongue-like form pos- 
teriorly. C. Troscheli, Benson (lxxvi, 93). 
THEOBALDIUS, Nevill. Shell subdiscoidal, widely umbilicated ; 
peritreme circular, thickened, not much reflected, continuous. 
Asiatic. C. annulatus, Nevill (Ixxvi, 94). 
SCABRINA, Blanford. Shell depressed, subdiscoidal, widely 
umbilicated; epidermis hispid; whorls rounded; aperture 
circular, peristome thickened. Operculum thick, corneous, the 
margins of the whorls lamellately elevated. Asiatic. C. calyx, 
Benson (Ixxvi, 95). 
BUCKLEYIA, Higgins. Shell discoidal, widely umbilicated ; 
with revolving carine, and deciduous epidermis; aperture 
circular, vertical, margin continuous, adnate, thin, acute. So. 
America. C.. Martinezz, Hidalgo (Ixxvi, 96, 97). 
MIORAULAX, 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 
