182 EEPOET UNITED STATES GEOLOGICAL SUEVEY. 



12. Niicula planimarginata Meek & Hayden. 



The localities east of tlie Eocky Mountains in Colorado at wliich this 

 species has been found are the valley of the Cache a la Poudre, the 

 mouth of the Saint Vrains, and near Golden City, at all of which places 

 it seems to hold a position near the top of the Fox Hills Group. I am 

 not aware that it has anywhere been found at a lower horizon, it having 

 been found only in the Fox Hills Grou]3 of the Upper Missouri Eiver 

 region. 



13. Sphceriola? ohliqua Meek. 



The original descriiDtion of this species is in the Bulletin of the United 

 States Geological and Geographical Survey of the Territories, 2d series, 

 No. 1, p. 46, but it has never yet been figured. I found it only in the 

 •valley' of the Little Thompson. These and the type specimens are the 

 only representatives of the species yet discovered. The latter were found 

 some eighteen or twenty miles south westward from the locaUty of the 

 former. 



14. SpJiccriola ? endotracJiys Meek. 



The type-specimens of this species were obtained from " ninety miles 

 below Fort Benton on the Missouri, from Cretaceous beds holding a 

 position in the very upper part of the Fox Hills Group." I found it in 

 a similar position, associated with the foregoing species, in the valley of 

 Little Thompson Creek. It has never been reported as occurring else- 

 where. One of my examples especially shows a still greater degree of 

 roughness of the inner surface than is represented by Meek's figures. 



15. Tancredia americana Meek & Hayden. 



The first known specimens of this species were obtained " from a Cre- 

 taceous bed holding a position in the very upper beds of the Fox Hills 

 Group at the mouth of Judith Eiver on the Upper Missouri." I obtained 

 it in the valley of the Cache ii la Poudre, and at the mouth of the Saint 

 Yrains, where it holds a similar position. I am not aware that it has 

 ever been found at a lower horizon, and it may therefore be regarded 

 as one of the species which characterize the very highest strata of undis- 

 puted Cretaceous age in ISTorth America. 



18. Tancredia ? ccelionotus White. 



One of the types of this species, which is described and figured in 

 another part of this report, was recognized in a collection sent to the 

 Survey by Mr. J. C. Hersey from '' the Cache a la Poudre, ten miles 

 west of Greeley, Colo." Only two examples of it have been discovered, 

 the exact locality of the other not being accurately known. 



17. Yeniella Jmmilis Meek & Hayden. 



Dr. Hayden first discovered this species in the Fox Hills Group, on a 

 branch of Cheyenne Eiver, near the Black Hills. I obtained a goodly 

 number of s]3ecunens of it, well preserved, in the valleys of the Cache a 

 la Poudre and Little Thompson Creek. At both these localities it 

 seems to hold a position above the middle of the Fox Hills Group, as 

 it is developed east of the Eocky Mountains in Colorado. So far as I 

 am aware, it has never been found west of the Eocky Mountains. 



18. Cardimn speciosmn Meek & Hayden. 



This seems to be a widely distributed species, and to characterize the 

 uppermost layers of the nndisputed Cretaceous rocks of the West, where 

 alone it has been found in the Upper Missouri Eiver region. The lowest 

 horizon at which it is known to have been found is that of the strata at 



