SPH/ERIUM. 3T 



tf 



The specimens from which I have prepared this description 

 were presented to the Academy of Natural Sciences of Philadel 

 phia by Mrs. Say, as the C. triangularis, Say ; they may or may 

 not be true representatives of Say s species. In many points they 

 answer his description of the C. triangularis, but at the same 

 time I am not able to reconcile their shape, which is not more tri 

 angular than that of any other species, with the name he has 

 applied to the species. Moreover, they bear a very strong re 

 semblance to one of our Northern Sphserium, the S. solidulum; 

 they differ from it, however, in being less heavily and more regu 

 larly striated, and in having more prominent beaks. 



5. Spliaerium striat ilium, LAMARCK. . Fig. 29. 

 Animal white, tubes light reddish yellow. 



Shell slight, transversely elongated, somewhat 

 compressed, inequilateral; anterior margin rounded, 

 posterior distended, inferior rounded ; beaks full, 

 not much raised ; sulcations irregular, at times so 

 light as hardly to be seen with the naked eye, thus 

 giving the shell a lustrous appearance ; color vary 

 ing from a light greenish-yellow to a darker shade ; s. striatinum. 

 valves slight ; interior blue ; hinge-margin slightly 



curved ; cardinal teeth double, very small, of the same size ; lateral teeth 

 larger, not very prominent. 



Long. 0.43 ; Lat. 0.31 ; Diam. 0.25 inches. 



Hob. North America, in the States of New York, Connecticut, New Jer 

 sey, Pennsylvania, Michigan, Illinois, Ohio, Wisconsin, Alabama, Ten 

 nessee, Iowa, in the Hell Gate River, Washington Territory, and in Canada. 

 (Cabinets of the Academy of Natural Sciences of Philadelphia, Smith 

 sonian Institution, Jay, Prime, and others.) 



Cydas striatina, LAMARCK, An. s. vert. V, 1818, 560. 

 Cydas edentula, SAY, N. Harm. Dissem. 1829, 2. 

 Cydas cornea, LAMARCK, C. B. Adam s Cat. 1847. 

 Cydas albula, PRIME, Host. Proc. IV, 1851, 155. 

 Cydas tenuistriata, PRIME, loc. sub. cit. IV, 1851, 156. 

 Cydas acuminata, PRIME, loc. sub. cit. IV, 1851, 158. 

 Cydas inornata, PRIME, loc. sub. cit. IV, 1851, 159. 

 Cydas simplex, PRIME, loc. sub. cit. IV, 1851, 159. 

 Cydas modesta, PRIME, loc. sub. cit. IV, 1851, 159. 



As may be seen by the above synonymy, I have been induced to 

 unite under this species several which I described as distinct in 



