WHITE.] FOSSILS OF LITTLE THOMPSON CREEK. 177 



4. Inoceramns ohlongns Meek. 



5. Inoceramns vanuxcmi IMeek & Hayclen. 



6. Cardium speciosum ]\Ieek & Hayden. 



7. CalUsfa deiceyi Meek & Hayden. 



8. Mactra {Cymhopliora) warrenana Meek & Hayden. 



9. Ghjhcmeris bcrfhondi Wliite. 



10. Anchnra haydeni AVhite. 



11. Bacidites ovatus Say. 



12. Scaphites nodosus Owen. 



13. Placenticeras placenta var. He Kay sp. 



The different species composing this list will be discnssed on following 

 pages, in connection with those of other lists obtained fi'om other local- 

 ities in this tlistrict. 



The jnnction between the Fox Hills strata at or in the \dcinity of 

 Fossil ividge, and the Colorado Gronp beneath them, was fonnd to be 

 everywhere covered by the debris of the plains, but it is i)robably not 

 more than one or two hundred feet beneath the lowest strata exposed 

 at that locality, as all the strata begin almost immediately to rise rap- 

 idly to the foot-hills. I desired very much to know the aggregate thick- 

 ness of the Fox Hills Group of this region from that jimction to the 

 highest strata of the series, at Marcks's farm, but on account of the 

 obsciu-ation of a large part of the series, and the varying dip, I found 

 myself unable to estimate it with any good degree of satisfaction. 



Proceeding southward from Fossil Creek to the valley of Thompson 

 Eiver, I examined its valley, without adding materially to the facts 

 already enumerated. I then crossed southeastwardly to the Little Thomp- 

 son Creek, in the south valley side of which I found some exposures of" 

 Cretaceous strata, the aggregate exposed thickness of which is apparently 

 not above 40 or 50 feet. Here I made the collections of the following 

 list, which, it will be seen, corresponds more nearly with those obtained 

 iu the valley of the Cache a la Poudre than with the Fossil Eidge col- 

 lection, a list of which has just been given. It differs somewhat, how- 

 ever, from the collection obtained from the upper layers as they are^ 

 found both at Marcks's farm, on the Cache a la Poudre, and at the mouth 

 of the Saint Vrains, which latter locality will presently be noticed. I 

 therefore regard these strata in the valley of Little ThomiDSon Creek as 

 holding a position intermediate between the strata of Fossil Eidge and. 

 those of the summit of the group as develojDed in this district. 



LIST OF FOSSILS COLLECTED IN THE VALLEY OF LITTLE THOjMPSON: 



CREEK. 



1. Crenella elegantula Meek & Hayden. 



2. Spha^riola ? ohliqua Meek. 



3. tiphicriola f endotrachys Meek. 



4. Veniella liumilis Meek «& Hayden. 



5. Cardium speciosum Meek & Hayden. 



C. Frotocardia rara Evans & Shumard sp. 



7. Frotocardia suhquadrata Evans & Shumard sp. 



8. CaUista deiceyi Meek & Hayden. 



9. Tellina scitula Meek & Hayden. 



10. Thracia fjraciUs IMeek «& Hayden. 



11. Teredo ? borings in fossil wood. 



12. Lunatia "? 



13. Anchnra americana Evans & Shumard sp. 



14. Fseudohuccinum nebrascense Meek & Hayden. 



12as 



