8*2 THE NAUTILUS. 



rotund Jit us, ad finem brevissime et leviter subascendens. Apertura 

 parum obliqua, subcircularis, intiis luteola. Peristoma subinter- 

 ruptum, anguste, ad columellam paulo niagis expansiusculum. 



Diam. 9, alt. 9^, alt. apert. vix 5 mill. 



Hab.: Region of Fort Dauphin, S. Madagascar (F. Sikora). 



Although this small species bears some resemblance with others, 

 like C. undatoliratum Boettg., etc., still I cannot identify it with 

 any of them. 



Gyclostoma obsoletum Lam. 



Hab.: Province of Boeni. 

 Cyclostoma filostriatum Sowerby. 



Hab.: Fort Dauphin (F. Sikora). 



About the geographical distribution, it may be of interest to note 

 that Helicoplianta magnified has been found in Imerina, where it is 

 said to be very scarce (Sikora), and Heliophanta cornu-yiyanteum, 

 Chemnitz, in southern Madagascar, near Fort Dauphin (Sikora). 



NOTE ON NEOCORBICULA FISCHER. 



BY W. II. DALL. 



In a small collection of freshwater shells from Uruguay, recently 

 received, are specimens of Corbicula obsoteta Deshayes and C. Umosa 

 Maton. Tlie latter is the C. varieyata Orbigny, and the type of 

 Fischer's section Neocorbicula, proposed for the American Corbiculas, 

 which have separate siphons and a small pallial sinus, while the 

 European types of the genus Corbicula have an unsinuated pallial 

 line. 



Several of the specimens above mentioned hud the animal matter 

 dried up within the shell, and in removing this it was discovered that 

 the shells contained a large number of nepionic young of varied size, 

 some nearly two millimeters in length and already showing radiating 

 lines of color. There were 15 to 20 of the young fry in each indi- 

 vidual, and while the dried matter gave no distinct indication of the 

 original arrangement, the fry in each case were in the umbonal 

 cavities. 



