1903-] Hay, North American Cretaceous Fishes. 55 



VI, 1898, p. 226, fig. 2; Bibliog. and Cat. Foss. Vert. N. A. 1902, 

 p. 384. — LooMis (F. B.), Palseontogr. XLVI, 1900, p. 244. — 

 Stewart (A.), Univ. Geol. Surv. Kansas, VI, 1900, p. 296, pi. 

 xlix, figs. 1-3. — Woodward (A. S.), Cat. Foss. Fishes, IV, 1901, 

 p. 100. 



Portheus arcuatus Cope (E. D.), Vert. Cret. Form. West, 1875, p. 274, 

 pi. xlvii, figs. 7-9. 



This is one of the commoner species found in the Niobrara 

 beds of Kansas, and it has been figured by Cope, Crook, Hay, 

 and Stewart. As shown by some of the published figures and 

 by specimens in the American Museum, the mouth has been 

 very oblique. The eyeball is large, as shown by the pre- 

 served sclerotic bone. 



Crook has figured portions of the shoulder girdle and the 

 first pectoral ray. As in the case of Portheus, he has mis- 

 taken the upper end of the clavicle for the lower, and conse- 

 quently the right for the left fin. The first pectoral ray has 

 the same structure as that of Portheus, but has evidently been 

 proportionately shorter and more curved distally. 



An examination of the original of Cope's figures 7-9, pi. 

 xlvii, ' Vertebrata of the Cretaceous Formations of the West, ' 

 has convinced me that they belong to this species and not to 

 Gillie lis arcuatus. Crook has already surmised this to be true 

 (Palaeontogr., XXXIX, p. 112). The skull is shorter and 

 broader and of heavier construction. 



After examining skulls of Portheus, Saurocephalus, and 

 Gillicus I am confirmed in my opinion that the parietals are 

 united in the mid-line and lie in front of the supraoccipital. 

 They form the base of the great crest at the back of the 

 head, and extend slightly backward on each side like the 

 horns of a crescent. Posteriorly these horns join the an- 

 terior prolongations of the epiotics. I have not been able in 

 any case to discover sutures between the parietals and the 

 epiotics, but doubtless these exist. 



No. 2005 of the American Museum was collected in 1877, 

 in Gove County, Kansas, by Russell Hill. It furnishes a 

 complete head, 19 anterior vertebrae, the shoulder girdle, and 

 the first rays of both pectoral fins. Unfortunately, the head 



