272 



1. Cyclas rhomboidea Say. 



Jour. Ac. Nat. Sci. II, 380. De Kay, 225. PI. XXV. Fi?. 263. 

 Cyclas elegans Adams. Bost. Jour. Nat. Hist. III. PJ. III. Fig. 11. 

 Gould's Pveport, 74. Fig. 55. De Kay, 224. 



Cabinet of the B. S.N. H. 



Animal. Siphons reddish yellow. Foot large. 



Shell. Vide Gould's Rep. 74. 



Localities. Mass., Vt. (Adams.) Lake Champlain. (Say, 

 Budd, Benedict.) Herkimer County, N. Y. (Lewis.) Rock- 

 land County, N. Y. (Budd.) Cleveland, O. (Anthony.) Green- 

 wich, Washington County, N. Y. (Ingalls.) 



This shell has long been known as C. elegans Adams, and 

 been labelled thus in cabinets. It, however, answers Say's 

 description of C. rhomboidea^ in all points, even to the dimen- 

 sions, so that I have no hesitation in considering it as Say's long 

 lost species. 



Compared to the C. tenuistriata, it is found to be more full at 

 the posterior extremity, as also more abrupt ; the beaks are less 

 tumid and more rounded ; the coloring and sculpturing are dif- 

 ferent. 



This species has hitherto been collected but sparingly. Mr. 

 T. J. Whittemore, however, in the autumn of 1851, found it in 

 great abundance in the environs of Cambridge, Mass. It lives 

 in running brooks, buried in the mud, and in the grass. I sup- 

 pose the animal to breed all the year round, having found the 

 young in company with the adult at all seasons. 



Found in company with Pisidium variahile, and with C. simi- 

 lis. 



2. Cyclas tenuistriata Nohis. Bost. S. N. H. Proc. iv. 156. 



Cyclas cornea Lamarck. Adams's Cat. 1847, 29. 



Cabinet of T. Prime. 



Shell. Vide Bost. S. N. H. Proc. iv. 156. 



Localities. Tennessee, (Adams.) Alabama, (Ingalls.) 



This species is distinguished from all American ones of its 



