376 GEOLOGICAL SURVEY OF THE TERRITOEIES. 



convex. I am not sure that it is a true Anomia, 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. It is quite 

 common, and all the specimens are convex valves. 



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



6. Inoceramus {somewhat like I. prohlematicus)', between Evanston and 



FortBridger. 



7. Cardium curttim, M. & H. ^ between Evanston and Fort Bridger. 



8. Cardium pauperculum, Meek ; Medicine Bow, Wyoming Territory. 



9. (7or&^^^ft?; Coalville, Utah. 



10. Euspira ? ; Coalville, Utah. 



11. Melanopsis ? ; Coalville, Utah. 



12. Potamides ? ; Coalville, Utah. 



13. Goniobasis 1 ; Coalville, Utah. 



There are several other univalves and some Bivalves in the collection 

 from Coalville that appear to be marine and brackish 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 included them in the list. 



TERTIARY SPECIES. 



1. Corhula pyriformis. Meek ; Bear Eiver City, west side of middle fork 



of Warm Spring Creek. 



2. Corhula Ungelmanni, Meek ; Bear Eiver City. 



3. Unio prisGus, M. & H. 



4. TJnio JDanw, M. & H.f ; Fort Steele, Wyoming Territory. 



5. Corbicula (VeloretinaJ BurJceei, Meek. 



6. Viviparus (Campeloma) macrospira, Meek. 



7. Pyrgulifera Jiumerosa, Meek. 



8. Planorlns (Menetus) ; 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 exceiJtions, however, all of the collections can be referred 

 with confidence to their proper geological horizons. 



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

 Box Elder CaSon, 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 I thiok 

 them more probably Carboniferous. The larger portion 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 

 Valley; but some of them, particularly 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 numerous, nor in a very 

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



