﻿103 . Paleontology 25 



pelecypod. The specimens are poorly preserved and the 

 specific characters are not. well shown. An average-sized speci- 

 men has a diameter oi\% mm. 

 Locality: — Logan, Utah. 



BRACHIOPODA 3I . 



Productella cf. spinulicosta Hall. 

 PI. I figs. 3-3a. 



Shell small, concavo-convex. Surface marked by obscure 

 concentric wrinkles and fine concentric striae. A few spine bases 

 are distributed irregularly over the surface. These are of circu- 

 lar form and are not connected with the short ridgelike elevations 

 which characterize P. spinulicosta. In the absence of short 

 ridgelike tubercles this form resembles P. pyxidatus. This shell 

 is evidently identical with the one which Meek identified as P. 

 subaculeatus (?) from the dark limestone of the White Pine 

 district, Nevada. There is no indication of rows of spine bases or 

 tubercles which characterize the species in New .York. 



It is not improbable that larger collections will require the 

 separation of these forms as a new species, which seems hardly 

 desirable with the present material. 

 . Locality: — Paradise P. O., Utah; Princeton, Montana. 

 Stropheodonta cf . macrostriata (Walcott) 



A few imperfect specimens from the East Fork of Rock Creek 

 are doubtfully referred to this form. 



Locality: — East Fork Rock Creek, Princeton Quadrangle, 

 Mont. 



Stropheodonta sp. 

 A single pedicle valve of an undetermined species occurs in the 

 collection. It is distinctly convex and marked by rather angular 



3I The types of the new species described in this paper belong to the 

 collections of the U.S. Geological Survey. 



32 The reader is referred to Bull. 87 U.S. Geol. Surv. for the synonymy of 

 the species described. The synonymy of the few species described in other 

 groups may be found in Miller's North American Geology and Paleontology. 



