no. 1648. CERTAIN CARNIVOROUS DINOSAURS— HAY. 355 



acetabulum of Creosaurus is relatively small, the neck above the pubic 

 and ischiadic processes broad, and the crest high above the acetabu- 

 lum. The notch above the pubic process does not extend backward 

 as far as the front of the acetabulum; but there is another ilium 

 in the U. S. National Museum (Cat. No. 2323), believed to belong to 

 Allosaurus fragilis, which is intermediate in the depth of this notch. 

 Whatever may be true of other parts of the skeleton of Creosaurus, 

 there do not appear to be any characters in the ilium that distinguish 

 it generically from Allosaurus. The metapodial whose measurement 

 was given by Marsh a has the same length relative to the length of 

 the ilium that the fourth metapodial of Allosaurus fragilis has to its 

 ilium, being about 40 per cent. 



Dr. S. W. Williston a has published a figure of a scapula, coracoid, 

 and some fore-limb bones which certainly differ from those of Allo- 

 saurus; but there is as yet no certainty that any of these belong to 

 Creosaurus. Osborn b has figured as that of Allosaurus a scapula 

 which differs greatly from that of Marsh's specimen and which 

 resembles closely Willistoivs figure of the scapula thought to belong 

 to Creosaurus. 



Osborn has likewise described and figured a skull as that of 

 Creosaurus; but he grants that the genus has not been clearly sepa- 

 rated from Allosaurus. When this figure is compared with that of a 

 skull identified by Osborn d as Allosaurus no important differences 

 are discoverable. 



The skull last mentioned and the scapula figured by Osborn belong 

 to the fine skeleton of a carnivorous dinosaur which is on exhibition 

 in the American Museum of Natural History in New York. It is 

 to be regretted that there has not yet appeared a full critical descrip- 

 tion of this animal. However, a popular account of it, authorized by 

 Professor Osborn, was published in December, 1907, c by Mr. Walter L. 

 Beasley, and was accompanied by three figures reproduced from 

 photographs. In this article Professor Osborn contributed a para- 

 graph in which he identified the reptile as Allosaurus. Almost 

 certainly, however, it is not Allosam'us fragilis, for various reasons. 

 While the length of the fore limbs of the American Museum speci- 

 men has almost exactly the same ratio to the length of the hinder 

 limb that we find in the type of Allosaurus fragilis, the various 

 segments of the fore limbs of the two are quite unlike. There 

 appears to be no good reason why one cannot rely on Marsh's figure 

 of the fore limb and shoulder girdle. In the New York specimen 

 the hand is relatively enormous, being fully as long as the humerus 



°Amer. Jour. Sci., XV, 1S78, p. 243. 



& Bull. Amer. Mus. Nat. Hist., XXII, 1906, p. 291. 



c Idem, XIX, 1903, p. 697, figs. 1, 2. 



a Idem, XXII, 1906, p. 286, fig. 2. 



e Scientific American, XCVII, p. 446. 



