141 



U. cocci nous, Lea. 



{], comitlaiiiitus, Solander. 



U. eU'^aiis, Lea. 



U. ellipsis, Tjca. 



U. gibbosiis, Btjtrncs. 



U. gracilis, Barnes. 



II. hoterodon, Lea. 

 U. liippopaeus. Lea. 

 U. iris, Lea. 

 U. ligameiitinns. Lain. 

 U. liiteolus, Lam. 

 U. multiradiatus. Lea. 

 U. nasutus, a^t/. 

 U. Novi-Eboraci, Lea. 

 U. occidens, Lea. 

 U. ocliraceus, -Swy. 

 U. parvus, Barnes. 

 U. pliaseolus, i^jVc?. 

 U. pressus. Lea. 



U. pustulatus. Lea. 

 U. radiatus, Xam. 



U. rectus. Lam. 



U. rosaceus. Be Kay. 



U. rublgiuosus, Zea. 



U. spatulatus. Lea. 



U. Tappauiaiius, Xea. 



U. triangularis, Barnes. 



U. trig-onus, Xea. 



U. undulatus, Barnes. 



U. ventricosiis, Barnes. 



Robinson. 



Aldricli ; Dowcy ; Ingalls ; Lewis ; Skillton. 



lloltinson. 



Robinson. 



Lewis ; Robinson. 



Dewey; Robinson. Said to occur in Lake 



Champlain. 

 Robinson. 



Buffalo River (W. W. Stewart). 

 Dewey. 

 Robinson. 



Dewey ; Lewis ; Robinson. 

 Robinson. 



Aldricli ; lugalls ; Robinson. 

 Dewey; Jewett (Lockport) ; Robinson. 

 Robinson. 



Aldricli ; Lewis ; Skillton. 

 Robinson. 

 Robinson. 

 Aldricb ; Ingalls ; Lewis (Owasco Lake outlet) ; 



Robinson. 

 Robinson. 

 Aldricli; Dewey; Ingalls; Jewett; Lewis; 



Skillton. 

 Dewey ; Ingalls (Lake Champlain) ; Robinson 

 Dewey ; Jewett. 

 Dewey; Robinson. 

 Robinson. 



Aldricb ; Lewis ; Skillton. 

 Robinson. 

 Robinson. 

 Robinson. 

 Jewett (Lockport); Robinson. Said to occur 



in Lake Champlain. 



Subgenus MARGARITA NA, ScJium. 



M. com plana t a, Barnes. 

 M. Hildrctliiana, Lea. 

 M. margaritifera, Lin. 

 M. marginata. Say. 

 M. rug'osa, Barnes. 



M. undnlata. Say. 



Robinson. 



Buffalo River (W. W. Stewart). 



Reported orally. liocalities not known. 



Aldrich ; Lewis ; Robinson. 



Aldrich ; Dewey ; Jewett ; Lewis ; Robinson ; 



Skillton. 

 Aldrich ; Dewey ; Lewis ; Robinson ; Skillton. 



