no. 1648. CERTAIN CARNIVOROUS DINOSAURS— HAY. 359 



which had a D-shaped section belonged in fact to an animal distinct 

 from the one which possessed the saber-shaped teeth. The writer 

 regards as remote the contingencies under which this is possible. 



Leidy applied the name Deinodon to teeth of various forms and 

 sizes, without specifying any as types. Cope was the first who 

 restricted the name and he a applied it to those teeth with the 

 D-shaped section; and as first reviser his act must be respected. 

 Leidy's having first mentioned the saber-shaped teeth in his descrip- 

 tion, and given them a lower number on his plate certainly have 

 nothing to do with the matter, and his subsequent application of the 

 name Aublysodon to the teeth with D-shaped section can avail nothing 

 against Cope. On this point Canon XXI of the American Orni- 

 thologists Union's Code of Nomenclature and the remarks following 

 it may be consulted. 



To the present writer it seems that there are only two possible con- 

 ditions under which- Aublysodon may become available. The first is 

 that hereafter it shall be found that the name Deinodon had been 

 employed for some animal before its use by Leidy. The second is 

 that it shall at some time be shown that the tooth represented by 

 Leidy's figures 35 and 3f> belonged to one genus, while that repre- 

 sented by figures 37—10 belonged to another. In such a case it may 

 possibly be allowable to employ Deinodon horridus for one tooth, 

 Aublysodon mirandus for the other. The teeth represented by 

 Leidy's figures 41-45 are excluded, inasmuch as Leidy expressed a 

 doubt respecting their relation to the other teeth. This expression of 

 doubt renders nugatory Marsh's restriction of the name mirandus to 

 these teeth. ** 



5. OBSERVATIONS ON THE SKULL OF CERATOSAURUS NASICORNIS 



MARSH. 



The skull which forms a part of the type of Marsh's Geratosaurus 

 nasicornis belongs to the IT. S. National Museum and bears the cata- 

 logue No. 4735. 



During its entombment this skull became somewhat distorted and 

 much compressed, so that its thickness, from side to side, is now only 

 about 4 inches. Marsh's figures present a somewhat restored view 

 of the skull. Furthermore, at the time that these figures w T ere made 

 the matrix had not been removed from the orbits and the antorbital 

 vacuities, and consequently the bones of the palate were not depicted. 

 However, the matrix seems to have been removed at the time that 

 Marsh wrote the description for his Dinosaurs of North America. 

 Inasmuch as this is probably the most complete known skull of a 

 carnivorous dinosaur, it has been thought proper to present photo- 



"Proe. Acad. Nat. Sci. Phila.. 1866, p. 279. 

 & Amer. Jour. Sci., XLIV, 1892, p. 174. 



