358 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



regards the alveolar partitions, there appears to be little difference. 

 On this point compare Cope's description a and that of Lambe on 

 page 16 of his paper cited above. 



That Albertosaurus is distinct from Deinodon is still more doubt- 

 ful. Osborn has presented what he regards as the probable characters 

 of the latter genus. 6 Now, of the maxilla and the mandible of 

 Deinodon nothing is known ; hence nothing of the alveolar partitions 

 and triangular interdental plates. It is not known that the anterior 

 mandibular teeth were large and truncate in cross section. The 

 small tooth with D-shaped section which was figured by Leidy c may 

 have occupied the place of first mandibular incisor, just as it does in 

 Albertosaurus sarcophagus. 11 What the structure of the premaxillary 

 teeth of Deinodon was is not known. It is in the premaxillse that 

 may have been inserted those large teeth with D-shaped section that 

 are represented by Leidy's figures 35-40 of the plate cited. Drypto- 

 saurus, as represented by Cope's Judith River dentary, was, at most, 

 probably not far removed from Deinodon, and in close proximity to 

 that dentary Cope found a large tooth with D-shaped section. This 

 he thought had been in the position of an upper canine ; but it might 

 quite as well have been an upper incisor. In case all the teeth orig- 

 inally referred by Leidy to Deinodon really belonged to one animal, 

 it seems to me that the present evidence indicates that the small 

 teeth with D-shaped section belonged in the front of the lower jaw, 

 while the large teeth with similar section belonged in the premaxillse. 

 And the writer sees nothing to exclude Albertosaurus sarcophagus 

 from association with the species of Deinodon. 



It may not be improper to remark here that Osborn erred when he 

 stated' that the present writer has held the view that the name 

 Dt inodon is invalid. The writer needs only cite a paper in the Amer- 

 ican Geologist f and his Bibliography and Catalogue of Fossil Verte- 

 brata of North America " to show that he has both used and defended 

 the use of Deinodon. Nor is it correct to say that Cope rejected the 

 name because of the indefiniteness of the type. Cope regarded the 

 name as preoccupied by I) inodon of Dumeril and Bibron, as I have 

 shown in the article cited in the American Geologist. 



In his interesting paper here considered Osborn appears to imply 

 that Leidy's generic name Aublysodon may become available in case 

 it shall be shown that those teeth originally referred to Deinodon 



"I'roe. Acad. Nat. Sei. Phila., 1S70, p. 342. 

 6 Bull. Amer. Mus. Nat. Hist., XXI, 1905, p. 261. 

 'Trans. Amer. Philos. Soc, XI, 1859, pi. ix. figs. 41-4H. 

 <*Lambe, Contrib. Canad. Palseont., III. Pt. 8, p. 11. 



c Contrib. Canad. Palseont., HI, 1902, p. 18; Bull. Amer. .Mus. Nat. Hist., 

 XIX. P. Kir,, p. 259. 

 t Vol. XXIV, 1899, p. 346. 

 ^Page 488. 



