WHITEAVES.] LARAMIE AND CRETACEOUS INVERTEBRATA. 711 



tion of 0. congesta, and appear to be e^sentiallj- similar to the fussiU 

 from the Pembina Escarpment which Dr. Dawson has referred to that 

 species on page 79 of his British Xorth American Boundary Commi^- 

 .-•ion Report. 



Pteria (Oxttoma) Xebrascaxa, Evans and Shumard. 



Ai-iri'h XJji-iisrrnm^ Evans and Shumard. 1837. Traas. Ac. Sc. St. Louis, vol. I. 

 p. 38. 



" Meek. 18,59. HiiidV Eep. Assinib. and Saskatch. Expl. Exp., 



Toronto, p. 183, pi. 1, fig. 7. 



PUrki {O.ciiiuuvn Xehrih-^c'jno, 3Ieek, lS7fi, Eep, V. S. Geol. Surv. Terr., vol. IX, 

 p, 34, pi. If;, fi'^.s. 3 a, b, and pi. 28, fig. 11. 



Eocky Spring Eidge, near MacLe )d Benton Trail ; Milk Eiver, about 

 three miles we^t of crossing of MacLeod Benton Trail; and Tvest tiank of 

 "West Butte, Montana, in the Sweet Grass Hills, near to the international 

 boundary line ; G-, M, Daw:,on, 1S31: a few recognizable specimens from 

 each of these localities. 



XucuLA CAN'CBLLATA, Meek End Hayden. 



yijcvlii ca,.rel/,jtii, ileek & Hayden. 18.56. Proc. Ac. Nat. Sc. Phil., vol. YIIL, 

 p. 85. 



Meek. 1876. Eep. Geol. Surv. Terr., vol. IX, p. 102, pi. 28, ti-> 

 13 a,b, c, d, e. 



Milk Eiver, at the mouth of Pa-kow-ki Coulee, and Milk Eiver, four 

 miles east of the crossing of MacLeod Benton Trail, G. M. Dawson, 1881 . 

 apparently common at both of these places. The specimens are precisely 

 similar both in shapje and sculpjture to the beautiful fossil mentioned on 

 pages .37-38. 



Mactba (( 'rjiBOPHORA) GRACILIS, Meck and Hayden. 



M'octiv graciU!<,:sIeek and Hayden, 18(iO, Proc, Ac, Nat, Sc. Phil,, vol. XIL, 



p. 1711. 

 M'jctra ( C'l/mhophorii ) gracilis, ileek. 1876. Eep. 1'. S. Geol. Surv. Te;'r 

 IX, p. 20i),pl. 17, fig.s. l.s, a, b. 



Milk Eiver, at the mouth of Padvow-ki Coulee, G. ,M. Dawson, 1881 : 

 one very imperfect specimen with only small fragments of the test 

 preserved. 



