376 GEOLOGICAL SURVEY OF THE TEERITOEIES. 



convex. I am not sure that it is a true Anomiay as its form is 

 rather unusual for a species of that genus, being more like that 

 of Ostrea or GrypJicea^ to one of which it may possibly belong; 

 in which case the valve I have described as the upper would be 

 the lower. I should have referred it to one of these genera, but 

 for the fact that it seems to be entirely without a cardinal area, 

 and the casts of the interior show no traces of the muscular 

 cicatrix, usually' so well defined in those genera. Jt is quite 

 common, and all the specimens are convex valves. 



5. Inocerannis (one or two species) ; Coalville, Utah. 



G. Inoceramus (somewhat like J. jfjro6?c»iflf/c?fs); between Evanston and 

 Fort Bridger. 



7. Cardium ciirtiim, M. & H. ; between Evanston and Fort Bridger. 



8. Cardium imuiwrculum^l^lQQk) Medicine Bow, Wyoming Territory. 



9. CorhidaV, Coalville, Utah. 



10. JEiispira ? ; Coalville, Utah. 



11. Melanopsis'^.] Coalville, Utah. 



12. Fotamides^:', Coalville, Utah. 



13. Goniobasis ? ; Coalville, Utah. 



There are several other univalves and some bivalves in the collection 

 from Coalville that appear to be marine and bracldsh water types ; but 

 as they are imperfect specimens, imbedded in a hard, gritty matrix, I 

 have not had time to work them out so as to determine their affinities, 

 and consequently have not iucluded them in the list. 



TERTIARY SPECIES. 



1. Corljula pyriformis^ Meek ; Bear River City, west side of middle fork 



of Warm Spring Creek. 



2. Corhula Engelmanni, Meek; Bear liiver City. 



3. Unio ^?>'J6'CMS, M. & H. 



4. Unio Bcnicv, M. & H.!; Fort Steele, Wyoming Territory. 



5. Corhicida fVeloretinaJ iJurlceiyMeek. 



G. Viviparus (CampelomaJ macrospira^ Meek. 



7. Pyrgidifera Immerosa^ Meek. 



8. Flanorhis (Menetiis) ; Bear Eiver, 3 miles from Soda Springs. 



The condition of most of the fossils enumerated in the foregoing list 

 is such, that from a mere preliminary examination, it is scarcely possible, 

 in a majority of cases, to do more than refer them to their proper genera. 

 The Carboniferous forms are especially difficult to make out, the speci- 

 mens being generally in a fragmentary condition, and imbedded in a 

 very hard matrix that renders it almost impossible to work them out. 

 With a few exceptions, however, all of the collections can be referred 

 with confidence to their proper geological horizons. 



The occurrence of llalysites catenularia in some of the lower beds at 

 Box Elder Canon, for instance, shows that some of these beds belong to 

 the Silurian system; while those referred to the Carboniferous are such 

 types as are alone found in rocks belonging to that period, with possibly 

 the exception of a few from a locality half-way between Mantua and 

 Cache Valley, which may prove to be of Devonian age, though 1 think 

 them more probably Carboniferous. The larger i)ortion of these Car- 

 boniferous forms also seem to be most nearly allied to species found in 

 the upper members of the Lower Carboniferous of the Mississippi 

 Yalley; but some of them, i)articularly the Polyzoa^ are very closely 

 allied to forms found in the Coal-Measures in some of the Western States. 



The Jurassic fossils in the collection are not immerous, nor in a very 

 good condition, but they can readily be connected by the presence of 



