4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 97 



* 



The identification of this species is nf)t altogether certain, l)ut 

 as far as the state of preservations allows, careful comparison seems 

 to indicate that it should he so identified. 



Localities 55c and 556. 



Cotypcs. — U.S.N.M. no. 15315; plesiotypes, no. 96492. 



WORMS 



SELKIRKIA Walcott, 191 1 

 SELKIRKIA SPENCEI, n. sp. 



Plate I, figs. 34, 35 



This species from the Spence shale averages smaller than S. 

 major. The rate of taper is also less, so that the margins of S. spcncci 

 are almost parallel. 



Localities 55c, 556, and 54L. 



Cotypcs. — U.S.N.M. no. 96493. 



BRACHIOPODA 



MICROMITRA Meek, 1873 

 MICROMITRA LEPIDA, n. sp. 



Plate I, figs. II -13 



This species is characterized by its large size, many of the shells 

 measuring 10 mm long and 7 mm wide. The ventral valve is rather 

 highly elevated. The dorsal valve preserves internal markings which 

 are the first to he found in any species of the genus. The surface of 

 ])oth valves is ornamented with the usual strong growth lines, and 

 both valves show fine ribbing. 



Locality 55c. 



Cotypcs.— U.S.N.M. no. 51458. 



IPHIDELLA Walcott, 1905 

 IPHIDELLA GRATA, n. sp. 



Plate I, figs. 14-18 



This brachio])od was referred by Walcott to /. paiiintla, but its large 

 size alone distinguishes it from the numerous species referred to 

 /. pannula, except certain ones in the Grand Canyon and from lo- 

 calities northward of Montana. The characteristic ornamentation is 

 beautifully developed and covers practically the entire shell with 

 equal intensity. The hinge line is rather long and on the dorsal valve 



