22 



THE NAUTILUS. 



pressus Lea, 



pressus Lea, 



rangianiis Lea, 



Kirtlandiana Lea, 



triangularis Lea, 

 tuberculatus Barnes, 

 undulatus Barnes, 

 verrucosus Barnes 

 (rare). Very large. 



rubiginosus Lea 



(common), 

 rectus Lam., 



pressus Lea. 

 pustulatus Lea (rare). 

 pustulosus Lea. 

 pyraraidatus Lea. 

 raugiauus Lea. 

 rubiginosus Lea. 



(common), 

 rectus Lam. 



? ? 

 sul)rotundus Lea. 

 triangularis Lea. 

 tuberculatus Barnes, 

 undulatus Barnes, 

 verrucosus Barnes 



(rare). 



THE SHELL-BEARING MOLLUSCA OF RHODE ISLAND. 



BY HORACE F. CARPENTER. 



FAMILY UNIONIDJE. 



189. — Unio radiatus. 

 Syns. : 



Mya radiata, Gm. Dill. Wood. 



Mya ohlonga, Wood. 



Lamjosilis radiata, Stimp. Morse. 



Unio Virginiana, Lam. 



Unio radiata, modern authors. 



Shell transversely oblong-ovate, broader and angular behind ; 

 beaks nearer the anterior extremity ; epidermis concentrically 

 wrinkled, olivaceous with numerous lines of a greenish color radiat- 

 ing from the beaks to the margin ; nacre bluish-white, irridescent 

 at the posterior portion, Avith flesh colored tints ; cardinal teeth 

 strong, erect, triangular pyramidal. Length 3 inches, height li'o, 

 breadth li. 



It inhabits ponds and rivers on the eastern slope of the Allegha- 

 nies and is quoted as being one of our most common species, but it is 



