141 



U. coccineus, Lea. 



U. complaiiatus; Solandcr. 



U. elegaiiSj Lea. 



U. ellipsis, L^ea. 



U. gibbosus, Barnes. 



U. graciliSj Barnes. 



U. heterodon, Lea. 

 U. liippopaeus, Lea. 

 U. iris, Lea. 

 U. ligamentinus, Lam. 

 U. luteolus, i«?ft. 

 U. luultiradiatiis, Lea. 

 U. iiasutus, -S«^. 

 U. Novi-Eboraci, Lea. 

 U. occidens, Lea. 

 U. ochraceus, /Say. 

 U. parvus, Barnes. 

 U. pliaseolus, iZzM. 

 U. pressus, Lea. 



U. pustulatus. Lea. 

 U. radiatiis, i«»i. 



U. rectus, Lam. 



U. rosaceus. Be Kay. 



U. rubiginosns, Xea. 



U. spatulatus. Lea. 



U. Tappaiiianus, Zea. 



II. triangularis, Barnes. 



U. trigonus, iea. 



U. undulatus, Barnes. 



U. ventricosHS, Barnes. 



Robinson. 



Aldricli ; Dewey; Ingalls; Lewis; Skillton. 



Robinson. 



Robinson. 



Lewis ; Robinson. 



Dewey; Robinson. Said to occur in Lake 



Champlain. 

 Robinson, 



Buffalo River (W. W. Stewart). 

 Dewey. 

 Robinson. 



Dewey ; Lewis ; Robinson. 

 Robinson. 



Aldrich ; Ingalls ; Robinson. 

 Dewey; Jewett (Lockport) ; Robinson. 

 Robinson. 



Aldrich ; Lewis ; Skillton. 

 Robinson. 

 Robinson. 

 Aldricli ; Ingalls ; Lewis (Owasco Lake outlet) ; 



Robinson. 

 Robinson. 

 Aldrich; Dewey; Ingalls; Jewett; Lewis; 



Skillton. 

 Dewey; Ingalls (Lake Champlain); Robinson 

 Dewey ; Jewett. 

 Dewey; Robinson. 

 Robinson, 



Aldrich ; Lewis ; Skillton. 

 Robinson. 

 Robinson, 

 Robinson. 

 Jewett (Lockport); Robinson. Said to occur 



in Lake Champlain. 



Subgenus MARGARITA NA, Sclmm. 



M. complanata, Barnes. 

 M. Hildrctliiana, Lea. 

 M. margaritifera, Lin. 

 M. luarginata. Say. 

 M. rugosa, Barnes. 



M. undulata. Say. 



Robinson. 



Buffalo River (W, W. Stewart). 



Reported orally. liocalities not known. 



Aldrich ; Lewis ; Robinson. 



Aldricli ; Dewey ; Jewett ; Lewis ; Robinson ; 



Skillton. 

 Aldrich; Dewey; Lewis; Robinson; Skillton. 



