181 



~ SyiJ-.ii:MUS LATIFRONS, Cope. 



Keprcsciiied \)y tlic entire 1ic;kI and liody ol' a fish as far as tlic l)asis 

 of tlic ventral fins, excei)ting the end of the muzzle. The scales are com- 

 pletely j)reserved, while only the bases of the fins remain. 



Tin; l)ody is subcylindrie, while tin; head is broad and flat above. The 

 inferior side of the head is contracted; the coracoids forming a keel, and the 

 lower borders of the dentary bones being in contact. The angular portion 

 of the dentary is strongly grooved on its inferior surface, and the proximal or 

 anterior parts of the operculum display a radiate sculpture. The top of the 

 head is smooth, excepting a slight radiate sculpture of the parietals. The 

 outline of the parietals is subround, and a little more extended than that of 

 the siipraoccipital, wliich is a short longitudinal oval. 



There arc twenty-six or twenty-seven longitudinal rows of scales, or 

 thirteen on each half; tlio.-^e of the abdomen not differing from fiiose of the 

 sides. The lateral line runs along the eighth below the dorsal fin, originating 

 just'above the base of the pectoral fin. There are nine rows of scales between 

 the occi[)ut and the first dorsal ray. I count the bases of fifteen dorsal radii, 

 which are all fissured anteriorly, excepting the first, which is rudimental. 

 The anterior rays are stouter than the posterior, and they embrace the pos- 

 terior part of the ray in front of them by the basal fissure. The posterior 

 rays are mucli narrowed, and embrace l)ut little. The pectoral rays are 

 namerous. The physiognomy of this fish is rendered peculiar by the depressed 

 form of the snout, with the narrow under jaw. It is impossible to be sure 

 whether the muzzle was elongate or not. 



Measnreinents. 



M. 



Lciij;tli of the s)peciiiicn (o the l)a.so of tlio veutral liii ('. '*05 



Lcimlli (>f tlic specimen to flic base of the dorsal 0.090 



I.ciigtli of tlio .'.pccinii'ii to tho base of the pectoral ". 'i7."> 



Length of the ppecinicii to the edge of the operculum 0. 071 



Length of the specimen to tho eilgo of the preopcreulum CO.").') 



Length of the specimen to tho condyle of the mesoptorygoid 0.021) 



Lcngtli of tho specimen to the orbit 0.017 



Diameter of the front between the orbits 0.020 



Diameter of the body at the middle of the dorsal tin 0. 04.''> 



Depth of the body at the middle of the dorsal fin 0.050 



The specimen was found by Lieut eiianl Marsiiall, of the AV heeler United 

 Stales Geographical Survey, "near the siimmif of Pike's Peak," Colorado. 

 The specimen has the appearance ol' having been derived iioui tiie Cretaceous 



