584 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



diapopliyses, and thirty are without them. The anterior caudal dia- 

 pophyses are broad and flat ; the distal caadals have free chevron- 

 bones. The extremity of the muzzle is conic and depressed. 



LIODON Owen. 



Cope, Eep. U. S. Geol. Sarv. Terrs., (4to), ii, p. 160. 



LiODON, species undetermined, and 



Ltodon, second species undetermined, from AYestern Kansas, from 

 Mr. Sternberg. 



PLATECARPUS Cope. 



Eep. U. S. Geol. Surv. Terrs., (4to), ii, p. 141. 



Platecarpus ictericus Cope. 



Loc. cit., p. 144. 



Platecarpus coryphaeus Cope. 



Loc. cit., 142. 



All of the above species from Western Kansas. 

 ANOGMIUS Cope. 



Proc. Amer. Philos. Soc, 1871, p. 170 ; Eept. U. S. Geol. Surv., Hayden, ii, p. 240. 



A nearly complete skeleton of a species of this genus enables me to 

 give its characters in much greater completeness than has been possi- 

 ble heretofore. It appears that it is, in several primary characters, Phy- 

 sostomous and Isospondylous ; i. e., the maxillary bone enters the arcade 

 of the mouth ; there are no anteriorly-placed ventral fins, and the 

 scales are cycloid ; the anterior vertebras are unmodified, and the pa- 

 rietal bones are not separated from each other by the supra-occipital. 

 The dorsal fin originates above the base of the pectoral, with a num- 

 ber of strong osseous rays; it continues as far as the specimen is 

 preserved in that region, viz, to above the fifteenth vertebra, behind 

 the scapula, and the rays regularly diminish in strength. The inter- 

 neural bones continue further. A dorsal fin, whether the first or a 

 second, is not determinable, terminates a short distance in advance 

 of the caudal fin. Pectoral fin attached by two stout bones to the 

 upper part of the scapular arch. Anal fin posterior, below a part of the 

 dorsal fin, furnished with one stout, compressed, anterior spine. Five 

 vertebrpe included within the space inclosed by the anterior projection 

 of the borders of the caudal fin, forming a series slightly curved up- 

 ward. They diminish rapidly in size, and the last is confounded with 

 its neural spine. The terminal hsemal spines are all coossified into a 

 nearly equilateral fan-shaped body with a convex posterior border. 



The vertebrae are shorter than wide, but not excessively short ; the 

 neural spines are long and slender; and there are no diapophyses. The 

 ribs are long, and there are long superior supernumerary ribs. I have 

 not been able to find the lateral line, which may be because many of the 

 scales are not well preserved. 



