82 THE NAUTILUS. 



rotundatus, ad finem brevissime et leviter siibascendens. Apertura 

 parum obliqua, subcircularis, intus luteola. Peristoma subinter- 

 ruptuni, aiiguste, ad coliimellam paulo magis 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. 



Cyclostoma ohsoletum Lam. 



Hab.: Province of Boeni. 

 Cyclostoma filostriatuni Sowerby. 



Hab.: Fort Dauphin (F. Sikora). 



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



that Helicophanta magnijica has been found in Imerina, where it is 



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



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



NOTE ON NEOCORBICULA FISCHER. 



BY W. H. DALL. 



In a small collection of freshwater shells from Uruguay, recently 

 received, are specimens of Corbicula obsoleta Deshayes and C. limosa 

 Maton. The latter is the G. variegnta 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 iiave an unsinuated pallial 

 line. 



Several of the specimens above mentioned had 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 sliowiug radiating 

 lines of color. Tiiere 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. 



