122 



BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 



The best specimen (No. 6183, U.S.N.M.) consists of an excellently preserved 

 femur, tibia, and fibula of the left side (the latter lacking its distal half) , from Alkali 

 Creek, Niobrara County, Wyoming. Collected by' J. B. Hatcher in 1891. 



This specimen was referred b}>" Marsh in 1896 to Ornithomimus grandis (p. 206, 

 Dinosaurs of North America). The large size of these bones and their very close 

 resemblance to the same elements in Tyrannosaurus as described and figured by 

 Osborn clearly indicate their generic affinities, which are more in accord with their 

 geological occurrence, as Tyrannosaurus remains at the present time are known 

 only from the Lance formation or its equivalent, whereas the genotype of Orni- 

 thomimus grandis was found in the much more ancient Eagle formation. 



The principal dimensions of these bones as compared with the genotype of 

 Tyrannosaurus are given below. 



Greatest length of femur 



Mid diameter of shaft 



Greatest transverse diameter of condyles 

 Greatest length of tibia. 



No. 6183, 



U.S.N.M. 



No. 973, 

 A.M.N.H. 



mm. 



1,300 

 180 

 340 



1,140 



A second specimen (No. 2110, U.S.N.M.), represented by metatarsal IV of the 

 right hind foot and lacking the proximal end, has about the same dimensions as 

 given by Osborn for metatarsal IV of the genotype of Tyrannosaurus. It is esti- 

 mated that the complete length of this bone would be about 590 mm., and the 

 greatest diameter anteroposteriorly is 100 mm. This is probably the same bone 

 mentioned by Marsh l as Ornithomimus grandis. He says : 



In the other specimen the second metatarsal is in fair preservation and shows the same form as in 

 the type of the genus. 



This specimen was collected by J. B. Hatcher from the Lance formation on 

 Lance Creek, Niobrara County, Wyoming, in 1890. 



A third specimen (No. 8064, U.S.N.M.) is provisionally referred to this genus. 

 It consists of a right ilium, collected by J. B. Hatcher and A. E. Sullins, October 

 16, 1891, on Alkali Creek, Niobrara County, Wyoming. This specimen, except for 

 its smaller size, closely resembles the ilia of Tyrannosaurus as described by Pro- 

 fessor Osborn. 



DEINODON ? GRANDIS (Marsh), 1890. 



Ornithomimus grandis Marsh, Amer. Journ. Sci., ser. 3, vol. 34, p. 85, 1890; Sixteenth Ann. 

 Rept. U. S. Geol. Surv., pt. 1, p'. 296, 1896.— Hay, O. P., Bull. No. 179, U. S. Geol. Surv., p. 

 494, 1901.— Nopcsa, F. Baron, Foldtani Kozlony, Budapest, vol. 31, p. 201, 1901.— Osborn, 

 H. F., Contr. Canadian Paleont., vol. 3, pt. 2, p. 13, 1902.— Hatcher, J. B., Bull. U. S. Geol. 

 Surv., No. 257, pp. 12, 41, 87, 1905.— Bowen, C. F., Prof. Paper U. S. Geol. Surv., 901, p. 134, 

 1915.— Osborn, H. F., Bull. Amer. Mus. Nat. Hist., vol. 35, art. 43, pp. 470, 741, 1917. 



Type material. — Location of type unknown. Marsh in his original description 

 mentions only the third metatarsal, but Hatcher states 2 that it consists of "frag- 



i Dinosaurs of North America, p. 206, 1896. 



2 Bull. U. S. Geol. Surv. No. 257, p. 87, 1905. 



