136 



BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 



Locality. 1 — Near foot of the bluffs on the south banks of the Missouri River, 

 opposite Cow Island, Montana. 



Horizon. — Judith River formation, 2 Upper Cretaceous. 

 The original description is as follows: 



One of these, which may be called Ornithomimus tenuis, was about twice the bulk of the present 

 form [0. velox]. The third metatarsal was much more compressed transversely, both in the shaft and 

 distal end. The bone was also much more slender medially than in the above species. The transverse 

 diameter of this metatarsal at its distal end was 30 mm., and the anteroposterior diameter 35 mm. 



The above quotation gives prac- 

 tically all that had been written of 

 this specimen, although it has been 

 in the United States National Museum 

 since the transfer of the Government 

 collection from New Haven in 1899. 

 Until recently it was unrecognized as 

 being the type of this species. It 

 was not distinctively marked, but 

 that it does represent the specimen 

 on which Professor Marsh established 

 Ornithomimus tenuis appears to be 

 indicated: First, by the exact agree- 

 ment with the measurements given 

 by Marsh of the distal end; second, 

 it agrees with the brief description, 

 especially as to the great transverse 

 compression of the shaft ; third, it was 

 marked as being metatarsal III. In- 

 quiry discloses that the type specimen 

 is not in the Yale University collec- 

 tions, and it is the only specimen in 

 the United States National Museum 

 collections that comes anywhere near 

 filling all requirements. It would 



fig. 7o.-d IS tal half op metataksal in, ornithomimus tenuis seem > therefore, that there can be 

 marsh, left pes. type, no. 5814, u.s.n. m.; a, viewed from little doubt that this is the original 



back; B, viewed from left side; C, viewed from the front. _ :____ i," i, tv/t _ i. t, Ji.r i. - 



d, viewed from distal end; All figures \ natural size, specimen which Marsh had bef ore him 



when describing the above species. 

 The chief features of the specimen are clearly shown in figure 70, where the 

 type specimen is illustrated for the first time. 



1 This is the precise location given by Hatcher (Science, vol. 16, p, 831, 1902), but with the specimen there was a label that 

 contained the following information: " Birch Creek, Montana, J. B. Hatcher, July 3, 1818 (1975) Box 5." This label also had 

 written on it the same accession and box number as was painted on the type specimen, and this led me to believe it was written 

 for this particular specimen, and I so wrote Professor Osborn prior to the appearance of his bulletin on Struthiomimus, Ornitho- 

 lestes, and Tyrannosaurus. 



1 Hatcher estimates the geological position of this specimen to be as follows (see Osborn, H. F., Science, vol: 16, p. 675, 

 1902): "From 1,500 to 1,600 feet below the summit of the Judith River beds and 500 to 600 feet below the level of Marsh's 

 type of Ceratops monlanus." 



