not more than three or four species having been obtained beyond those 

 above referred to. 



Among the Cretaceous fossils there are many forms of great interest, 

 especially among the Inocerami and Cephalopoda. Among the former 

 the forms described under the new generic name of Endocostce are in- 

 teresting as affording light on a group of shells that, although long 

 known, have not been fully understood, probably owing to the want of 

 more and better material which this collection has afforded, the feature 

 there described having been seen on isolated specimens, poorly pre- 

 served. 



Among the Cephalopods of the Cretaceous there are some fine exam- 

 ples of the aberrant forms of the Ammonite group, which show very 

 conclusively that a rich field awaits the future collector in this region. In 

 some of the localities of this formation, from which collections have 

 been brought, there appears to be a difficulty in recognizing the divis- 

 ions of the group, proposed by Messrs. Meek and Hayden, as the fossils 

 of two of the divisions are found intermingling at the same place and 

 in the same layers. The specimens brought from the locality, on Old 

 Woman's Fork of the Cheyenne, are of this character, and there seems 

 to be the same trouble among those from certain parts of Beaver Creek. 

 The collection affords no specimens belonging strictly to the Divisions 

 No. 1 and No. 3, though the beds were observed but not collected from. 



