PISIDIUM. 71 



Cyclas pulchella,* D OKBIONY, Guer. Mag. Zool. 1835. 

 Pisidium pulchellum, DESHAYES, Biv* Brit. Mus. 1854, 283. 

 Pisum pulchellum, DESHAYES, Biv. Brit. Mus. 1854, 283. 

 Musculium pulchellum, ADAMS, Rec. Gen. II, 1858, 452. 

 Sphaerium pulchellum, PRIME, Proc. Acad. Nat. Sci. Phila. 1860, 297. 



It has not been my good fortune to meet with this species, 

 which M. D Orbigny likens to P. foniinale, of France ; he found 

 it in considerable abundance. 



12. Pisidium ferriigiiieum, 2 PRIME. Shell small, rounded- 

 oval, globose, slightly inequilateral ; anteriojr side some 

 what produced ; margins rounded ; beaks tubercular at Fig. 77. 

 apex, very distant ; surface smooth ; epidermis light 

 yellow ; hinge-margin rounded ; cardinal teeth large, 

 separate, anterior tooth more prominent ; lateral teeth 

 distinct. 



Long. 0.17; Lat. 0.13; Diam. 0.11 inches. 



Hob. North America, in the States of Maine and New p. ferrugineum. 

 York. (Cabinets of the Boston Society, Smithsonian 

 Institution, Lewis, Jay, and Prime.) 



Pisidium ferrugineum, PRIME, Bost. Proc. IV, 1851, 162. 



Remarkable for the elevation of its beaks, which stand forth on 

 the upper portion of the shell in the shape of large tubercles, 

 which are generally coated with some dark ferruginous substance. 

 It differs from P. abditum in being smaller, more inflated, not so 

 elongated, and more equilateral. 



One of our most common species, found usually in company 

 with P. variabile and P. ventricosum. 



Fig. 78. 



P. ferrugineum. 



1 Not to be confounded with Cyclas pulchella, HANLEY, or Pisidium pul 

 chellum, JENYSTS, a variety of P. casertanum, POLL 



2 Not to be confounded with Pisum ferrugineum, DESHAYES, Biv. Brit. 

 Mus. 1854, 281, which is Sphaerium ferrugineum, KRAUSS, of Africa. 



