white.] FOSSILS OF THE FOX HILLS GROUP. 185 



31. Actceon icoosteri White. 



In the district here discussed this species was found only at the mouth 

 of the Saint Vrains. A couple of examples found by Mr. W. H. Holmes 

 on the Eio San Juan, in Southern Colorado, seem to be specifically iden- 

 tical with the Saint Vrains specimens. It is figured and described in 

 another part of this volume. 



32. Actceonina prosoclieila White. 



This species has been recognized nowhere except at the mouth of the 

 Saint Vrains, where the type specimens were discovered. It is figured 

 and described in another part of this volume. 



33. Lunatia subcrassa Meek & Hayden. 



In the uppermost strata of the Fox Hills Group, on the Cache a la 

 Poudre, I found a number of specimens which evidently belonged to this 

 species, the type specimens of which were obtained by Dr. Hayden from 

 a similarly high position in the upper Fox Hills strata at the mouth of 

 Judith Eiver. Imperfect examples of a species of Lunatia were also 

 found at the Little Thompson Creek and Saint Vrains localities, but they 

 appear to belong to L. concinna Hall & Meek. 



34. Ancliura haydeni White. 



This remarkably large and fine species has been found only at Fossil 

 Eidge, and in strata that belong near the base of the Fox Hills Group, as 

 it is developed and recognized east of the Eocky Mountains in Colorado. 

 It is figured and described in another part of this volume. A calcareous 

 substance was found almost entirely encrusting the spire of the typical 

 example, which is apparently that of a Wullipora. At first I supposed 

 it to be an encrusting callus formed by the mollusk itself, such as that 

 of Calyptrwphorus Conrad and Lispodesthes White; but careful examina- 

 tion shows it to be parasitic, or at least not connected with the shell. 



35. Ancliura americana Evans & Shumard. 



The types of this species were obtained from beds in the Upper Mis- 

 souri Eiver region, in which were found a mixture of the characteristic 

 fossils of the Fox Hills and Fort Pierre Groups respectively. In the 

 region here discussed I found the species only at the Little Thompson 

 Creek locality. Some fragments, apparently belonging to this species, 

 were found in the valley of the Cache a la Poudre, but they were too 

 imperfect for satisfactory determination. 



36. Pseudobuccinum nebrascense Meek & Hayden. 



This species, originally discovered in the strata of the Fox Hills Group 

 of the Upper Missouri Eiver region, was found holding a similar position 

 in the valley of Little Thompson Creek. It seems to be a rare species. 



37. Fasciolaria (Piestocheilus) culbertsoni Meek & Hayden. 



Imperfect specimens of a species of this genus were found at the mouth 

 of the Saint Vrains, and also in the valley of the Cache a la Poudre. I 

 have referred them to F. (P.) culbertsoni, but their specific identification 

 is not quite satisfactory, x>artly inconsequence of the imperfection of the 

 specimens and partly owing to the difficulty I have encountered in recog- 

 nizing, in the specimens I have examined, the specific differences relied 

 upon by the authors quoted in separating their published species. 



38. Baculites ovatus Say. 



This widely distributed species was found at Fossil Eidge, but it has 

 not been discovered in the upper strata of the Fox Hills Group in the 



