0. P. Hay — Species of Saurocephalus. 299 



Akt. XXXII. — On one little known and one hitherto unknown 

 species of Saurocephalus ; by O. P. Hay. 



The fish Saurocephalus lanciformis was first described and 

 named by Dr. Richard Harlan in 1824.* This desciTption and 

 the accompanying figures were reprinted in 1835 in the same 

 author's Medical and Physical Researches.! The specimen on 

 which the genus and species were based had been collected 

 about twenty years previously, by Lewis and Clark, at some 

 locality probably in northeastern Nebraska. It consisted of 

 the greater portion of the left maxilla ; but was described by 

 Harlan as belonging to the lower jaw. He also regarded it as 

 having belonged to a reptile allied to Ichthyosaurus. Louis 

 Agassiz first recognized the ichthyic nature of the remains:}; 

 (although he confounded them with an entirely distinct spe- 

 cies) ; and his conclusions were confirmed by Richard Owen.§ 

 Dr. Leidyl corrected Agassiz's errors, and gave more accurate 

 descriptions and figures of the maxillary than had been fur- 

 nished by Harlan. 



No remains of Harlan's species, other than the maxillary 

 referred to, have hitherto been described. Dr. E. W. HilgardT" 

 has reported the species as occurring in the Vicksburg group 

 of the Eocene, but the identification was undoubtedly erro- 

 neous. Dr. William Spillman** has also included this species 

 in his list of fossils belonging to the Tombigbee greensand of 

 the Cretaceous at Columbus, Miss. Although this identifica- 

 tion is less improbable than the former, we have nothing to 

 confirm its correctness. 



Notwithstanding the scantiness of the material belonging to 

 the type species, our knowledge of the genus Saurocephalus 

 has been greatly increased through the descriptions of closely 

 related and more perfectly preserved species. For this addi- 

 tional knowledge we are indebted to Cope and Newton, and 

 more recently to Alban Stewart, of the University of Kansas. 



For some time I have had in my possession some remains 

 which on examination prove, in my judgment, to belong to 

 Harlan's species. This material was collected for me in the 

 region of Butte Creek canon, south of Wallace, Kan. ; and 

 the horizon is undoubtedly that of the Niobrara Cretaceous. 

 My material consists of both the mandibles, the right maxilla, 

 the pterygopalatine arch and a few other bones. 



The maxillary (fig. 1) is rather short and deep. The portion 

 belonging in front of the palatine condyle is missing ; but the 

 condyle itself is present. The alveolar border is somewhat 



* Jour. Acad. Nat. Sci. Phila. [1], ill, pp. 331-337, pi. xii, figs. 1-5. 



f Med. Phys. Res., pp. 362-366, pi., figs. 1-5. 



\ Poiss. Foss., v, p. 102. § Odontography, p. 130, pi. 55. 



|| Trans. Amer. Philos. Soc, 1857, xi, pp. 91-95, pi. vi, figs. 8-11. 



■fT Report Geol. and Agric. Mississippi, 1860, p. 142. ** Op. cit, p. 389. 



