474 ' GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 



4. Myoplioria Mere casts, apparently of this genus. 



5. Macrodon Mere casts, apparently of this genus. 



6. Myacites Mere casts, apparently of this genus. 



devil's SLIDE, CINNABAR MOUNTAIN, YELLOWSTONE EIVER. 



Names. * Eemarks. 



1. Gryphcea calceola, Quenstedt, 



var. 



2. CuGullcea Internal cast, apparently of this 



genus. 



3. Camptonectes. 



4. Trigonia elegantissima, IMeek.* 



5. Corimya Montanaensis^^li^okA 



6. Myacites {Pleuromya) subcom- 



pressa, Meek. 



7. Pholadomya. 



8. Ammonites. 



CRETACEOUS LIST. 



NEAR THE MISSOURI RIVER, BELOW GALLATIN, MONTANA. 

 Names. Remarks. 



1. Ostrea anomioides, Meek. 



2. Trigonia Nearly allied to T. Evansi^ Meek. 



Same as No. 3, from Cinnabar 

 Mountain. 



3. Corbicula (Veloritina) mflexa^ 



Meek. 



4. Corhicula {Veloritina) Like the last, excepting that its 



beaks are more oblique, more 

 nearly terminal, and more de- 

 pressed. May be a variety of 

 same. 



5. Corhicula ( Veloritina) A small and proportionally shorter 



form. 



6. Cardium A rather small, nearly circular spe- 



cies, with fine radiating strise. 



7. Inoceramus Fragments. 



8. Fharella{1) FeaJeij'Meek. 



9. Avicula .. . Small species. 



10. Avicula (!) Small 5 of the type of A. raricostaj 



Eeuss. 



11. Modiola Small, smooth species. 



12. Mytilus Casts. 



13. Tellina Casts. 



14. Corhula. 



15. Anchura Eough mold in matrix. 



* A small species of the type of T. costata, but having the concentric or horizontal 

 costaj on the sides of the valves very delicate, closely arranged, and but slightly 

 larger than the radiating ones on the posterior dorsal region, or corselet. The valves 

 are rather compressed, about one-fourth longer than wide, and have the posterior 

 limbonal slopes acutely angular. 



t This is very similar to some varieties of C. glabra, Agassiz, but it is a smaller, pro- 

 portionally shorter, and more convex shellj with the anterior margins just in front of 

 the beaks more excavated. 



