Cope.] 536 [Nov. 18, 



M. 



Width hsemal spine of second of series : . . . .024 



Vertical diameter centrum first " 025 



Length of neural spine and centrum of anterior caudal 108 



Transverse diameter of neural spine " " at base 0235 



Antero-post. diam. four anterior caudal neural spines in contact. . .069 



Length centrum of a dorsal 04 



Vertical diameter " " 0615 



Transverse " "' " ("crushed) 041 



These remains were found in place by Prof. B. F. Mudge : he states 

 that their extent was eight feet. As they embrace no cervical vertebrae 

 nor portions of cranium, two feet are probably to be added, giving a total 

 of near ten feet for the length of this fish. It was discovered at a point 

 on the bank of the Solomon's or NepahoUa river, in Kansas, 160 mUes 

 from its point of junction with the Kansas river. 



SAURODON Hays. 

 Transac. Amer. Philosoph. Society, 1830, 476. 



Saurodon leanus, Hays. 

 Loc. cit. Tab. xvi. Leidy Trans. Am. Philos. Soc. 1856. 

 From the cretaceous green sand of JSew Jersey. 



ICHTHYODECTES. Cope, gen. nov. 

 In this genus the teeth are subcylindric and slender, without cutting 

 edges. The inner margins of the maxillary and dentary bone exhibit 

 no dental foramina, which are in SaurocepJialus and Saurodon, of large 

 size. 



ICHTHYODECTES CTENODON. CopC, Sp. ThOV. 



This species is established on one complete maxillary bone, and three- 

 fourths of the other, a large part of the dentary bone, with the entire 

 dental series ; numerous portions of cranial bones, with thirteen vertebrae. 

 These, according to Prof. Mudge, were found together, and to all ap.pear- 

 ance belong to the same animal. 



The dental characters differ from those of Saurocephalus, as above 

 pointed out, and in this species more than in 8. leanus. The crowns of 

 the teeth are more exserted and slender. The inner face of the crown is 

 more convex than the outer ; but there is no angle separating the two 

 aspects. The apex is moderately acute, and directed a little inwards, 

 owing to a slight convexity of the external face. Enamel smooth. The 

 alveoli are very close together, and are probably only separated in their 

 deeper portions. There are forty-two teeth and alveoli in the maxillary 

 bone. The palatine condyle is low, and its anterior border falls opposite 

 to the last tooth, or the indented surface which was occupied by the pre- 

 maxiUary bone. The more proximal part of the maxillary curves inwards 

 and backwards behind the position of the premaxillary more than in 8. 

 prognaiJius. The maxillary is a rather thin and narrow bone, with a 



