0ENITH0MI3IUS. 



205 



In fig. 3 of the plate the three phalanges represented belong with 

 the second metatarsal, and were found together in place. 



The three metacarpals represented in fig. 4 were found together in 

 position, near the remains of the hind limb here described. Their very 

 small size is remarkable, and they inay possibly belong to a smaller 

 individual, but with this exception there is no reason why they do not 

 pertain to the same specimen as the hind foot. The remains of this 

 species were found by George L. Gannon, jr., in the Ceratops beds of 

 Colorado. 



THE PELVIC ARCH. 



A larger species from the same horizon, Omithomimus sedens, more 

 recently described by the writer, is based upon the nearly complete 



FIG- 49. — Terminal phalanx, manus of Omithomimus sedens Marsh; side view. 



Fig. 50.— The same phalanx ; front view. 



Pig. 51. — The same; back view. 



Fig. 52. — Proximal end of same. 



All the figures are one-half natural size. 



pelvis, with various vertebra 3 , and some other parts of the skeleton. 

 The most striking feature of the pelvis is the fact that the ilium, 

 ischium, and pubis are firmly coossified with one another, as in recent 

 birds. This character has been observed hitherto among dinosaurs 

 only in the genus Ceratosaurus, described by the writer from the Juras- 

 sic of Wyoming. The preseut pelvis resembles that of Ceratosaurus 

 in its general features, but there is no foramen in the pubis. 



There are five vertebra; in the sacrum, firmly coossified with one 

 another, as are also the sacral spines. The sacral vertebra? are grooved 

 below, with the sides of the centra excavated. The caudals have the 

 diplosphenal articulation, and the first caudal bears a chevron. All 

 the bones preserved are very delicate, and some of them, at least, are 



