1903] Hay, North American Cretaceous Fishes. ^\ 



Saurocephalus arapahovius Cope (E. D.), Proc. Amer. Philos. Soc. XII, 

 1872, p. 343; U. S. Geol. Surv. Mont. 1872, pp. 344, 348; Bull. 

 U. S. Geol. and Geog. Surv. I, No. 2, 1874, p. 41; Vert. Cret. 

 Form. West, 1875, pp. 216, 275, pi. xlix, fig. 5. — Woodward 

 (A. S.), Cat. Foss. Fishes IV, 190 1, p. 114. — Hay (O. P.), Bib- 

 Hog, and Cat. Foss. Vert. N. A. 1902, p. 385. 



Saurocephalus arapalovius Loomis (F. B.), Palceontogr. XLVI, 1900, 

 p. 251 (syn. of 5. lanciformis) . 



The type of Cope's Saurocephalus arapahovius is in the 

 Cope Collection, now belonging to the American Museum of 

 Natural History, and has the number 2073. It is a fragment 

 of the maxilla. Cope distinguished his species from S. lanci- 

 formis on the ground that the facets shown by Leidy to exist 

 on the roots of the teeth of the latter were absent in the for- 

 mer. Loomis unites the two species because he regarded the 

 presence of facets to be variable. I have exposed the root of 

 one of the teeth of the type of 5. arapahovius and find that 

 there are very distinct facets. There appears, therefore, to 

 be no reason for retaining it as a distinct species. 



Saurocephalus xiphirostris (Stewart). 



Saurodon xiphirostris Stewart (A.), Kansas Univ. Quart. VII, 1898, 

 p. 178, pi. xiv; Univ. Geol. Surv. Kansas, VI, 1900, p. 314, pi. Iv. 

 — Loomis (F. B.), Palaeontogr. XLVI, 1900, p. 247. — Wood- 

 ward (A. S.), Cat. Foss. Fishes, IV, 1901, p. 113. 



Saurocephalus xiphirostris Hay (O. P.), Bibliog. and Cat. Foss. Vert. 

 N. A. 1902, p. 386. 



Saurodon phlebotomus hooMis (F. B.), Palaeontogr. XLVI, 1900, p. 248, 

 pi. xxiv, figs. 1-5. 



I find difficulty in estimating the value of Stewart's species, 

 Saurodon broadheadi, S. ferox, and 5. xiphirostris. There is 

 at least one good species among these; if only one, it must 

 bear the earliest name, broadheadi. S. ferox appears to differ 

 from 5. broadheadi in having the maxilla proportionally a 

 little higher. It has also an unusually large number of teeth 

 in the maxilla, 40; an unusually small number, 46, in the 

 dentary; and only 10 in the premaxilla. The number is 

 variable, however; a specimen. No. 16 14, referred to S. 



