vrcnTE.] FOSSILS OF LITTLE THOMPSON CEEEK. 177 



4. Inoceramus oblongus Meek. 



5. Inoceramus vanuxemi Meek & Hayden. 



6. Cardium speciosum Meek & Hayden. 



7. Callista deiceyi Meek & Hayden. 



8. Maetra (Cymbophora) warrenana Meek & Hayden. 



9. Ghjbcmeris berthoudi White. 



10. Anchu ra h ay den i White. 



11. Baculites ovatus Say. 



12. Scaphites nodosus Owen. 



13. Placenticer as placenta var. DeKay sp. 



The different species composing this list will be discussed on following 

 pages, hi connection with those of other lists obtained from other local- 

 ities in this district. 



The junction between the Fox Hills strata at or in the vicinity of 

 Fossil Ridge, and the Colorado Group beneath them, was found to be 

 everywhere covered by the debris of the plains, but it is probably 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 junction to the 

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

 obscuration 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 

 Fiver, 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 

 in 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 Thompson Creek as 

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

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



LIST OF FOSSILS COLLECTED TN THE VALLEY OF LITTLE THOMPSON: 



CEEEK. 



1. Crenella elegantula Meek & Hayden. 



2. Sphceriola ? obliqua Meek. 



3. Sphceriola % endotrachys Meek. 



4. Veniella Immilis Meek & Hayden. 



5. Cardium speciosum Meek & Hayden. 



6. Protocardia rara Evans & Shumard sp. 



7. Protocardia subquadrata Evans & Shumard sp. 



8. Callista deiceyi Meek & Hayden. 



9. Tellina scitula Meek & Hayden. 



10. Ihracia gracilis Meek & Hayden. 



11. Teredo % borings in fossil wood. 



12. Lunatia % 



13. Anchiira americana Evans & Shumard sp. 



14. Pseudobuccinum nebrascense Meek & Hayden. 



12 gs 



