ISOSPONDYLI. 73 



Dapedoglossus iEQUiPiNNis Cope. 



Bulletin U. S. Geol. Surv. Terrs., 1878, p. 77 (February 5). 

 Plate VU, fig. 2. 



Two specimens present the principal character of this species, viz, the 

 equality in number of rays in the dorsal and anal fins and the near equality 

 in their size. The radii are in one, D. 23 ; A. 22 : in the other, D. 22 ; 

 A. 22. In B. testis, the formula is D. II — 18 ; A. 11—26. The vertebrae 

 in one of the specimens of D. aquipinnis number D. 19; C. 27 : while in 

 D. testis there are, D. 18 ; C. 24-25. (The number, 21 dorsal, originally 

 given, must be corrected, as based on an imperfect specimen.) In D. (equi- 

 pinnis, the first pectoral ray is not so largely developed as in X). testis, not 

 being of unusual size The hyoid apparatus and vomer are closely studded 

 with teeth, as required by the generic character. 



Measurements. 



Length of No. 1 051 



Axial length of head of No. 1 014 



Axial length to line of anal fin 030 



Axial length to Hue of dorsal .028 



Axial length to origin of caudal 040 



Depth of head 012 



Depth at first dorsal ray 008 



Depth of caudal peduncle 004 



Length of No. 2 092 



Depth at middle of dorsal line 032 



Depth at base of dorsal fin 024 



Depth of caudal peduncle 008 



The specimens described are much smaller than those of the D. testis 

 yet known, and No. 1 is probably young. This fact will not account for 

 the peculiarity of the radial formula, etc. 



Green River shales at Twin Creek, Wyoming. 



DIPLOMYSTUS Cope. 



BuUetin U. S. Geol. Surv. Terrs., 1877, p. 808 (August 15). 



Family Clupieida;, and nearly related to the genus Clupea. It differs 

 from Clupea in the presence of a series of dorsal scuta, which extend from 

 the supraoccipital region to the base of the dorsal fin, con-esponding in 

 position with those of the ventral surface. Unlike these, they have no 



