2 Bulletin American Museum of Natural History. [Vol. XIX, 



paper. Of the drawings, Mr. R. Weber has made numbers 

 27, 58, 59, 60, 61, 62, and 65. All the others, except 32 and 

 72, have been prepared by Mrs. L. M. Sterling. The photo- 

 graphs for the plates have been made by Mr. A. E. Anderson, 

 photographer of the Palaeontological Department. 



PROTOSPHYR^NID^. 



The genus Protosphyrcsna is referred by Dr. A. S. Wood- 

 ward to the Pachycormidae ; and in this procedure he is fol- 

 lowed by Loomis (Palaeontogr., XLVI, 1900, p. 221), by 

 Stewart (Univ. Geol. Surv. Kan., VI, 1900, p. 362), and by 

 the present writer (Bibliog. and Cat. Foss. Vert. N. A., 1902, 

 p. 378). A reconsideration of the subject and the study of 

 the materials at hand in this Museum have led me to a differ- 

 ent view. 



If we refer the genus to this family we must assume that 

 the vertebral column was not at all ossified or only feebly so. 

 That it was composed of well ossified vertebrse cannot yet be 

 proved. However, accompanying the type of P . dimidiata 

 there is a single vertebra which belonged close to the skull. 

 It is figured on page 19. This vertebra may be an intrusion 

 from some other fish, but there is nothing in its appearance 

 to suggest this. 



So far as the writer can gather from the literature, neither 

 the Isopholidae, hitherto called Eugnathidse, nor the Pachy- 

 cormidae, possess ossified scapulae and coracoids. Even the 

 members of the more advanced family Amiidag, with well 

 developed vertebras, have scapulae and coracoids cartilagi- 

 nous. ProtosphyrcBna, on the other hand, has the elements 

 of the shoulder girdle developed as in the modern Isospondyli. 

 While there may be no necessary connection between an 

 ossified shoulder girdle and ossified vertebrae, it seems logical 

 to believe that, when the shoulder girdle is so advanced in 

 its development as it is in ProtosphyrcBna, there were probably 

 also well defined vertebrae. It is remarkable that vertebrae 

 have not been certainly collected, but neither has the tail fin 

 been obtained, nor the anal, nor the dorsal fin. 



It is proper to add to the above paragraph the statement 



