80 CONTRIBUTIONS TO CANADIAN PALyHONTOLOGT. 



LioPiSTHA (Cymella) undata, Meek and Hayden. 



Pholadomijauridata, Meek and Hayden. 1^56. Proc. Ac. Xat. Sc. Phil., vol. VIII, 



p. 81. 

 LiopUtliii (CijmeUa) undata, Meek. 1876. Rep. U. S. Geol. Surv. Terr., vol. IX., 

 p. 236, pi. 39, figs. 1, a, b. 



.Alilk Eiver, four miles east of MacLeod Benton Trail, G. M. Daw.son, 

 1881 : five well eharacterized specimens. 



CoRBULA PERTiNDATA ? Meek and Hayden: 



Corhvla pmmdata, ^Imk and Hayden. 1856. Proc. Ac. Nat. Sc. Phil., vol. VIII, 

 p. 116. 

 " Meek. 1876. Rev. U. S. Geol. Surv. Terr., vol- IX., p. .530, pi. 40, 



figs. 4 a, b, c, d. Figured also on plate 19, figs. 16 and 17, of Dr. 

 C. A. White's Eev. Non-Marine Foss. JIoU. N. Am. 



Eocky Spring Eidge, near MacLeod Benton Trail, G-. M. Dawson. 

 1881: a badly preserved right valve which is somewhat doubtfully 

 referred to this sjtecies. 



CoRBULAMELLA GREGARiA, Meek & Hayden. 



Corbvla? yregaria. Meek and Hayden. 1856. Proc. Ar. Nat. Sc. Phil., vol. VIII., 



p. 84. 

 CorhvJrimelln fjrcgirnn , Meek ct Hayden. 1857. 1\)., vol. IX., p. 143- 



Meek. 1876. Hep. V. S. Geol- Surv. Terr., vol. IX., p. 247, 



pi. 17, figs 13, a, b, c, d. 



AVest flank of AVest Butte, Montana, in the Sweet Gra^-^ Hills, near 

 the international boundary line. G. M, Dawson, 1881 . a number of per- 

 fect specimens crowded together in a small hand ^-peeimen of rock. It 

 is only upon the weathered outward surface of the rock, however, that 

 the outlines of the united valve^ can be clearly made out. and the char- 

 actei's of the interior of the latter are entirelv unknown. 



