GASTEROPODA. 



the extremity; anal siphon longer than in Ventalium^ not 

 fissured. 



Distribution, 2 species. China ; Atlantic. 



Fossil, 7 species. Cretaceous-Miocene. Paris ; United States. 



OeDER II. — PULMOISTFERA.* 



Family I.— HELicLD^.f 

 SOPHLN'A, Benson, 1859. 



Type, S. schistostelis, Bens. 



Shell like Eelix ; columella callous, with a basal slit. 



Distribution, 3 species. Moulmein. 



Cylikdrella (p. 293). 



Animal with no buccal plate; the lingual dentition varies 

 considerably in dijfferent species; in C. scceva, Guild., the for- 



. 26 . 1 . 26 , 

 mula is — rr-r — ; the central plate is small, obtusely pointed, 



the laterals are uncinated, joined two by two, upper edge 

 fringed. 



•* C. Goldfussi possesses 4 lamellae on the outer wall of the 

 whorls. The axis of C. turris and of some other Mexican spe- 

 cies is a highly polished tube, the young shells of which must 

 have a wide open umbilicus." — (Bland.) 



Macroceramus, Guilding. 



The genus has aflSnities with Bidimiis, Pupa, and Cylindrella. 



Animal with an arcuate and striated buccal plate ; lingual 



dentition distinct from that of Cylindrella; in M, signatus, 



27 . 1 . 27 

 Guild., = — !— -^ — , the central plate is narrow, with an obtuse 



tooth, laterals with one prominent tooth sup- 

 porting two denticles and a small one at the 

 base. 



Shell with the axis simple as in Bulimus ; 

 in M. amplus a lamella revolves on the axis 

 within the lower whorls. Fig.16. 



Distribution, 30 species. The genus belongs Central plate and 

 to the "West Indian fauna, and has its greatest m. signatus (Moise). 

 development in Cuba and Haiti. 



AcnATESTA. — Sub-genus, Geostilbia, Crosse, 1867. 



Type, G. Caledonica, Crosse. New Caledonica. 

 • See p. 285. t See p. 288. 



41 



