474 GEOLOGICAL SURVEY OF THE TERRITORIES. 



4. Myophoria Mere casts, appareutlj' of this ji^emis. 



5. Maerodon Mere casts, apparently of this genus. 



6. Myadtes Mere casts, apparently of this genus. 



devil's slide, cinnabar mountain, YELLOWSTONE RIVER. 



Niviues. Remarks. 



1. Gryplicva calceola, Queustedt, 



var, 



2. Cuculkca Internal cast, apparently of this 



genus. 



3. Camptonci'ics. 



4. Trigonia ekganfisslnia, Meek.* 



5. CorimyaMontanaeiisis, Me(}kA 



6. Myadtes {Pleuromya) subcom- 



pn\ssa, ]\Ieek. 



7. rholadomya. 



8. Ammonites. 



CRETACEOUS LIST. 



NEAR THE SnSSOURI RIVER, BELOW GALLATIN, MONTANA. 



Names. Remarks. 



1. Ostrea anomioldes^ Meek. 



2. Tr'ujonia Nearly allied to T. Evmisi, Meek. 



Same as No. 3, from Cinnabar 

 Mountain. 



3. Corhicida {Veloritina) injlcxa, 



Meek. 



4. Corhicida {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. Gardium A rather small, nearly circular spe- 



cies, with tine radiating striie. 



7. Inoceramus Fragments. 



8. FharcUa {'i) Fealei,Meek. 



9. Avicula Small species. 



10. Avicula i^l) Small ; of the type of A. raricosta, 



Reuss. 



11. Modiola Small, smooth species. 



12. MTjtilus. Casts. 



13. Tellina Casts. 



14. Corhula. 



15. Anchura Rough mold in matrix. 



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

 costic on the sides of the valves very delicato, closely arranged, and bnt slightly 

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

 are rather comj)ressed, al)out one-fourth longer than wide, and have the i^osterior 

 unibonal slopes acutely angular. 



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

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

 the beaks more excavated. 



