■H-HiTE.l CROW CREEK FOSSILS. 165 



if we except Volsella (Brachydontes) regularis White, a couple of imper- 

 fect examples of which were found among those forais. 



No. 6 ought, perhaps, to he properly subdivided, but, being composed 

 of soft material, it was found nowhere freely exposed. Some of the lay- 

 ers seem to have been of purely fresh- water origin, because fragments of 

 a species of Unio and one of Campeloma were found there 5 while other 

 layers were as evidently of brackish-water origin, because the Ostrea 

 before mentioned was frequently found in them, though it is not so abund- 

 ant there as in No. 4. Although these fragments of Unio were too im- 

 perfect for specific identification, they were sufficient for unmistakable 

 generic recognition, and their discovery has especial interest as being 

 the first recognition of that genus that has hitherto been made in the 

 strata of the Laramie Group east of the Eocky Mountains in Colorado, 

 although many species have been discovered in strata of that period west 

 of the mountains and in the Upper Missouri River region. 



Nos. 7, 8, 9, and 10 were found exposed only at one locality, in a gully 

 that led down to the creek. Their characteristics are doubtless repre- 

 sented with approximate correctness in the foregoing record of the sec- 

 tion, but they were not without some evidence of having been partially 

 disturbed by the valley erosion. Either No. 7 or No. 9, or both, probably 

 represents the bed of coal that is worked at Higley's Mine and elsewhere, 

 and is reported to have been worked in this neighborhood also, but I 

 did not find it. The following is a list of the fossils obtained from the 

 different members of this section : 



LIST OF FOSSILS FR03I THE VALLEY OF CROW CREEK, : COLORADO. 



1. Anomia micronema Meek. 



2. Anomia gryphorhynchus Meek. 



3. Ostrea glabra Meek & Hayden. 



1. Volsella (Brachydontes) regularis White. 



5. Anodonta parallcla White. 



0. Un io 1 



7. Corbicula cleburni White. 



8. Corbicula obesa White. 



9. Corbicula cardiniarformis White. 



10. Corbicula (LeptestJies) subelliptica Meek & Hayden. 



11. Corbicula (LeptestJies) fracta Meek. 



12. Corbicula (LeptestJies) macropistJia White. 



13. Corbicula (LeptestJies) planumbona Meek. 

 11. Corbula subtrig .leek & Hayden. 

 15. Bulinus disjunctus White. 



10. Bulinus subelongatus Meek & Hayden. 



17. Physa felix White. 



18. Goniobasis gracilienia Meek & Hayden. 



19. Goniobasis nebrascensis Meek & Hayden. 



20. Melania wyomingensis Meek. 



21. Viviparus prud'entia White. 



22. Tulotoma tJiompsoni White. 



23. Campeloma m ita Meek & Hayden. 

 2-1. Corydalitcs fecundum Scudder. 



NOTES ON THE LARAMIE FOSSILS OBTAINED IN THE VALLEY OF CROW 



CREEK, COLORADO. 



No. 1. Anomia micronema Meek. 



This species was originally described by Meek in the Bulletin of the 

 United States Geological and Geographical Survey of the Territories, 



