140 



BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 



by the decidedly deeper and more curved dorso-ventral concavity of the proximal 

 end, whether it is compared with Camptosaurus or Antrodemus . From the Orni- 



thopod foot it is further distinguished by the absence of 

 a deep median groove on the distal end and the presence 

 of well-defined lateral pits, as in Antrodemus and Ornitho- 

 mimus and probably all other Theropod foot bones. In 

 all Ornithopod feet these pits on the phalanges are either 

 illy defined or wanting. Its dimensions are as follows: 



mm. 



Length, taken at the center 69 



Width of proximal end 32 



Width of distal end 27 



Least transverse diameter of shaft 19 



Fig. 74. — Second phalanx digit ra, 



RIGHT, OF OENITHOMIMUS APFINIS, 

 NEW SPECIES. COTYPE NO. 5703, 



U.S.N.M. {A ) Anterior view, 



(B) LATERAL VIEW. BOTH FIGURES 

 J NAT. SIZE. 



The second phalanx, No. 8456, U.S.N.M., of digit IV 

 right hind foot is shown in figure 75. It has the usual 

 proximal ridge and distal groove, the deep lateral pits near 

 the distal end which clearly indicates the Theropod affini- 

 ties of this bone. 



This bone has a greatest length over all of 38 mm.; greatest width of proximal 

 end of 24 mm. ; greatest width of distal end of 24 mm. 



The ungual, No. 6107, U.S.N.M. (fig. 76), Lull describes as follows: 



The ungual, which is here referred to this species [Dryosaurus grandis] is compressed, triangular in 

 section, the upper face bearing a rather sharp ridge, which separates it from those of Laosaurus consors 

 those of Dryosaurus alius being unknown. It has a gentle curve with the characteristic slightly hollowed 

 under surface of Laosaurus and the smaller Camptosaurus species. 



Dimensions. 



mm. 



Length 55. 5 



Height 26. 



Width 17. 



That this ungual phalanx pertains to a member of the Theropoda is at once 

 indicated by its compressed shape, for among the dinosauria all 

 of the herbivorous forms, with the exception of the Sauropoda, 

 such as Laosaurus, Camptosaurus, Hypsilophodon, Thescelosuurus , 

 Trachodon, Corthyosaurus , Iguanodon, Scelodosaurus Stegosaurus, 

 Triceratops, etc., have depressed unguals. 



This bone is the same size as the ungual of- digit I of the 

 Ornithomimus foot, but I do not feel certain that it pertains to 

 that digit. With the exception of being narrower transversely 

 at the proximal end, it agrees closely in all other particulars. 



In addition to the type material enumerated above there 

 are two caudal vertebrae in the collection (Nos. 5701 and 6116, 

 U.S.N.M.) which are referred to this species, as is also the distal 

 end of a proximal phalanx No. 6115, U.S.N.M. These vertebrae are referred by 

 Lull to Allosaurus medius Marsh, but their close resemblance to the caudals of 

 Ornithomimus appears to indicate their Ornithomimid affinities. One of these is 

 illustrated in figure 77. 



Fig. 75.— Second phalanx 

 digit iv, right of orni- 

 thomimus affinis, new 

 species. cotype no. 

 8456, U.S.N.M. ANTERIOR 

 VIEW. J NAT. SIZE. (AF- 

 TER Lull.) 



