80 THE WASATCH AND BRIBGER FAHN^. 



ERISMATOPTERUS Cope. 



Annual Report U. 8. Geol. Snrv. Terra., 1870, p. 427. 



Dorsal and anal fins short, with two or three strong appressed support- 

 ing spines in front; no other interhaemal spines than those supporting those 

 of the anal fin. Dorsal fin above the anterior median or posterior abdom- 

 inal region. Ventrals originating in front of or opposite to the origin of the 

 dorsal. Pubes sending a limb upwards, which is in contact with the inferior 

 post-clavicle. Teeth minute or (I) wanting. Caudal fin bifurcate. 



I originally referred a species of this genus to the Cyprinodontida, and 

 many of the characters are similar to those of that family. The arc of the 

 mouth is formed by the premaxillary bone, and the ventral fins have a rather 

 anterior position, which is neither pectoral nor ventral, and the caudal is 

 furcate; the scales are cycloid. The strength of the spinous fin radii and 

 supporting interhfemal spines attracted my attention, and on careful exami- 

 nation I observe other approximations to the type of Asineops and the 

 Aphredodiridce. The inferior post-clavicle is very long and styliform, as in 

 the latter genus, and the pubic bones are slender and directed upwards, so 

 as to rest on the post-clavicles. In one specimen there appears to be an 

 anteriorly directed pubic limb, but this does not exist in other specimens. 

 The pubes do not reach the clavicles, as in true Physoclysti. Vertebrae 

 hour-glass shaped. Ventral radii seven, in the species E. rickseckeri and 

 E. endlichi. 



Erismatopterus levatus Cope. 



Annnal Report U.S. Geol. Sorv. Terrs., 1870, p. 428. Cyprinodon lecatui Cope. Proceed. Amer. Philoa. 



Soc, 1870,p.382. 



Plate rx, fig. 6-7. 



Anterior margin of anal fin commencing a little behind, opposite the 

 posterior margin of the dorsal. VertebrjE : 11-14-5, seven between the 

 interneural and interhaemal bones of the dorsal and anal fins. Radii: D. 

 8, A. II. 8, V. 8. Caudal fin deeply furcate; first anal ray strong. General 

 form elongate, the greatest depth contained three times in the length be- 

 tween the scapular arch and the basis of the caudal fin. Scales preserved, 

 small; seven longitudinal aeries above and seven below the vertebral 



