GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 337 



convexity was visible on the side of a bluff of clay-shale rock, with 

 seams and crystals of gypsum. The bones were all coated with a thin 

 layer of gypsum, and in some places their dense layer had been de- 

 stroyed by conversion into sulphate of lime. 



The habit of this species, like that of its nearest known allies, was 

 raptorial, as evinced by its numerous canine-like teeth and the fish-re- 

 mains taken from beneath its vertebrse. 



The general form of this reptile, whether it was furnished with large 

 iposterior limbs or not, was .that of a serpent, with a relatively shorter, 

 more robust, and more posteriorly placed body than is characteristic of 

 true serpents, and with two pairs of limbs or paddles. It progressed 

 by the strokes of its paddles, assisted by its powerful tail. The body 

 was steadied by the elevated keel of the median dorsal line, formed by 

 the broad, high neural spines. The snake-like neck was raised high in 

 the air, or depressed, at the will of the animal; now arched swan-like 

 preparatory to a x)luuge after a fish, now stretched in repose on the 

 water or deflexed in exploring the depths below. 



Localities. This species has been found in various parts of Kansas, 

 besides that whence the specimen above described was procured. Pro- 

 fessor B. F. Mudge obtained vertebrte from a point -thirty miles east of 

 Port Wallace, which probably belong to this animal. 



OENITHOSAUEIA. 

 OENITHOCHIRUS, Seeley. 



This genus embraces the largest of the pterodactyles or flying saurians. 

 Besides a great expanse of wings, they had strong claw-bearing digitis 

 in front, and a short tail. Their heads were slender and the teeth indi- 

 cate carnivorous habits. Two species were found by the writer in 

 Kansas. 



Oenithochikus umbeosijs. Cope, (Proc. Amer. Philos. Soc, March, 

 1872.) — One of the largest known species, having an exj)anse of wing of 

 nearly twenty-five feet. 



Oeotthoc'hirus haepyia, Cope, {loc. cit.) — A large species, but 

 smaller than the last, with a wing expanse of eighteen feet. This spe- 

 cies was abundant, and may be the one originally mentioned by Professor 

 Marsh under the preoccupied name of Fterodactylus owenii. 



PISCES. 



Large numbers of remains of fishes are found in the Niobrara chalk. 

 They are referable to three families and twenty-three species of physos- 

 tomous or soft-rayed fishes, with the addition of a few sharks. The 

 former were chiefly related to the salmon and to the pike, but were 

 more strongly armed for offense and defense than their recent repre- 

 sentatives. 



SAURODONTIDiE, Cope. 



Proc. Amer. Philos. Soc, 1870, p. 529 ; Hayden's Survey "Wyoming, &c., 1871, p. 414. ; 

 Proc. Amer. Philos. Soc, 1872, February. 



A considerable accession of material belonging to several species of 

 this family, furnishes important additions to our knowledge of their 

 structure, and enables me to determine their af&uities with more pre- 

 cision than heretofore. The results are of value to the student of com- 



22 G s 



