10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. sO 



Family NONIONIDAE 

 Genus NONION Montfort, 1808 



NONION GRATELOUPI (d'Orbigny) 



PLATE] 2, Figures 6 a, 6 



Nonian grateloupi Cxtshman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 10. 1930. 



There are numerous specimens of this West Indian species from 

 the three stations in Rio de eTaneiro Hai-bor, but it has not occurred 

 in any of the material from the region to the south. 



Genus ELPHIDIUM Montfort, 1808 



ELPHIDIUM POEYANUM (d'Orbigny) 



Elphidium poeyanum Cushman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 25, 1930. 



This species is the most abundant one in the West Indian region, 

 and it is therefore not surprising to find that it is common at all three 

 of the stations in Rio de Janeiro Harbor. These specimens are typi- 

 cal and show the very prominently perforate wall and the short retral 

 processes. It seems to be replaced in the colder water to the south 

 by the following species, 



ELPHIDIUM ARTICULATUM (d'Orbigrny) 



Elphidium articulatum Cushman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 26, 1930. 



D'Orbigny described this species from " the coast of Patagonia, 

 near Rio Negro, and also from the Falklands." It is fairly common 

 off the Falklands in shallow water and also occurs off St. Julian, 

 Argentina, and off Puerto Deseado, Argentina. These stations cor- 

 respond exactly with the distribution of the species as given by 

 d'Orbigny. This may be distinguished from E. foeyanum by the 

 highly polished and very finely perforate wall, the perforations being 

 so small that the wall appears entirely clear in many specimens. 



ELPHIDIUM INCERTUM (Williamson) 



Elphidium incertum Cushman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 18, 1930. 



A very few specimens in the collections from South America may 

 be referred to Williamson's species. They are not typical, however, 

 and possibly may have to be referred elsewhere. 



ELPHroiUM SAGRUM (d'Orbigny) 



Elphidium sagrum Cushman, U. S. Nat. Mus. Bull. 104, pt. 7, p. 24, 1930. 



The only specimen that can be referred to this West Indian species 

 is a single one from Rio de Janeiro Harbor. This specimen is typical, 



