DESCRIPTIONS OF SPECIES. 315 



Pleurotomaria 1 sp. h. 



As mentioned by White," among the impressions from Larimer County is one of 

 a small gasteropod shell. It consists of about four volutions which are flattened 

 above and angulated. The spire is high. This shell maj^ be a pleurotomarioid, but 

 in general configuration it presents many features in common Avith a form described 

 by White as Macrocheillna angulifera. It is much smaller than that species, however, 

 and more' slender, and probably was derived from a much earlier geologic period. 



Locality (uul horizon. — Pebbles of Millsap limestone (?) in the Red Beds 

 conglomerate, Larimer County (station 2364). 



BELLEROPHON Montfort, 1808. 

 Beiaerophon sp. 



At station 2350 in the Crested Butte district and station 2381 in the San Juan 

 region single specimens of Bellei'ophon. have come to hand, representing, not improb- 

 ably, the same species. As one specimen is an internal cast and the other is com- 

 pletely embedded in chert, but few characters of importance can be ascertained. 

 The species seems to be a large one and the axial diameter of the larger specimen (at 

 the aperture) is about -10 mm. ; the longitudinal, 15 mm. It somewhat resembles Bel- 

 Jerophon crassus and probably can be referred to the genus Bellerophon sensu stricto. 



Locality and hwlzon. — San Juan region (station 2381); Ouray limestone. 

 Ci'ested Butte district (station 2350); Leadville limestone. 



CRUSTACEA. 



PHILLIPSIA Portlock, 1843. 

 Phillipsia peroccidens Hall and Whitfield. 



1877. Proetus peroccidena (pars). Hall and Whitfield, U. S. Geol. Expl. 40th Par., Rept., vol. 4, 

 p. 262, pi. 4, figs. 31, 32, 30 (?), (non figs. 28, 29=Pkimpsia loganemis). 

 Waverly group: Ogden and Logan canyons, Wasatch Range, and Dry Canyon, Oquirrh 

 Mountains, Utah. 

 1887. Proetas jieroccidens (pars). Vogdes, New York Acad. Sci., Ann., vol. 4, p. 79. 



Waverly group: Ogden, Logan Canyon, Wasatch Range, and Dry Canyon, Oquirrh Moun- 

 tains, Utah. 



In discussing Proetm loganensla in 1899 * I expressed a doubt as to the propriety 

 of referring to P. peroccidens certain cephalic shields which, though associated with 

 the pygidia characteristic of that species, are ye,t very difl'erent in the character of 

 their surface ornamentation. The pygidium of P. peroccidens, it may be reiharked, 

 is highly ornamented with rows of nodes or pustules, while the surface of P. logam.- 



oU. S. Geol. «eog. Surv. Terr., Bull., vol. .i, 1879, p. 215. ^U. S. Geol. Surv., Mon., vol. 32, pt. 2, 1899, p. .578. 



