WHITEAVES.] LARAJIIE AND CRETACEOUS INVERTEBRATA. 27 



the test is preserved. Two casts of a Unio colJected by Dr. Dawson at 

 Pyramid Creek, in the same year and under the same auspices, may 

 possibly also belong to this species. 



CoRBULA 5IACTRIP0RMIS, Meek and Hayden. 



•Corbula mactriformis, Meek and Hayden. 1856. Proc. Ac. Nat. Sc, Phil., vol. 



VIII., p. 117. 

 Corbula {Potamoraya) mactriformis, M. & H. 1860. lb. vol. XII., p. 432. 

 Corbula mactriformis, Meek. 1876. Eep. TJ. 8. Geol. Surv. Terr., vol IX., p. 528, 



pi. 43, figs. 7, a-f. 



Wood End Depot, Souris Eiver, G. M. Dawson, 1874, H. M. North 

 American Boundary Commission : several perfect valves and a few 

 fragments, associated in the sam.e beds with Unio priscus. 



Thaujiastus ldin^iformis, Meek and Hayden. 

 Plate 3, flgs. 3a and 3b. 



£ulimusUmnxiformis,^le&k undB-^yden- 1856. Proc. Ac. Xat. Sc. Phil-, vol. 



Yin., p. 118. 

 Bxdinus Xehrascensis, Meek and Hayden. lb. 

 Thaumastus limnseiformis. Meek. 1876. Eep. U. S. Geol. Surv. Terr., vol. IX., p 



553, pi. 44, flgs. 8, a, b, c, d. 



Wood End Depot, Souris Eiver,— and Pyi-amid Creek, G-. M. Dawson, 

 1814, H. M. Xorth American Boundary Commission. Six specimens 

 from the first named locality and one fragment from the second, 



GoNiOBASis TENUicARiNATA, Meek and Hayden. 



Melania tenuicarinata. Meek and Hayden. 1857. Proc. Ac. Nat. Sc. Phil. vol. 



IX., p. 137. 

 Goniohagis tenuicarinata, Meek. 1876. Rep. U. S. Geol. Surv. Terr., vol. IX., 



p. 566, pi. 43, flgs. 14, a b, c. 



Pyramid Creek, G. M. Dawson, 1874, H. M. ISTorth American Boun- 

 dary Commission, one specimen. 



