152 BULLETIN 110, UNITED STATES NATIONAL MUSEUM. 



Plate 19. 

 Atlas and axis of Ceratosaurus. 



Figs. 1-5. Atlas of Ceratosaurus nasicornis Marsh. Type. No. 4735, U.S. N.M. I, inferior view; 2, top 

 view; 3, posterior view; 4, lateral view; 5, anterior view f (Seep. 94.) 



6-10. Axis of Ceratosaurus nasicornis Marsh. Type. No. 4735, U.S. N.M. 6, inferior view; 7, top 

 view; 8, posterior view; 9, lateral view; 10, anterior view, d., diapophysis; to., inter- 

 centrum of atlas; n., neurapophysis; n. p., neurapophysial processes; o., odortoid; p., 

 parapophysis; z., anterior zygapophyses; z' ., posterior zygapophyses. All the figures 

 are one-half nat. size. All except figure 2 are after Marsh. All drawn under the direc- 

 tion of Prof. 0. C. Marsh. (See p. 95.) 



Plate 20. 



Cervical vertebrae of Ceratosaurus. 



Figs. 1-4. Third cervical vertebra of Ceratosaurus nasicornis Marsh. Type. No. 4735, U.S. N.M. Fig. 

 1. Anterior view; 2, posterior view; 3, ventral view; 4, lateral view. All the figures are 

 one-half nat. size. (After Marsh.) (See p. 95.) 



5. Sixth cervical vertebra of Ceratosaurus nasicornis ; Marsh. Type. No. 4735, U.S. N.M. Lateral 

 view. One-half nat. size, d., diapophysis; o.s., dermal ossifications; p., parapophysis; 

 s., neural spine; z., anterior zygapophyses; z'., posterior zygapophyses; (After Marsh.) All 

 drawn under direction of Prof. 0. C. Marsh. (See p. '96.) 



Plate 21. 



Sacrum and pelvis of Ceratosaurus. 



Fig. 1. Sacrum and pelvis of Ceratosaurus nasicornis Marsh. Type. Cat. No. 4735, U.S. N.M. Ventral 

 view. 2. Same viewed from the front, ac, acetabulum; c^, caudal vertebrae 1 and 2; il., 

 ilium; i.p., ischiac peduncle; is., ischium; p., pubes; p. /., pubic foramen; pp., pubic 

 peduncle; p.s. 21, presacral 21; p.s. 23, presacral 23; r., posterior thoracic rib crushed back- 

 ward out of position; s., spinous process of dorsal vertebra; s^Ss, sacrals one and five. Both 

 figures drawn under the direction of Prof. 0. C. Marsh but certain features as explained in the 

 text are misleading. Both figures are one-fourth nat. size. (See p. 97.) 



Plate 22. 



Caudal vertebrae of Ceratosaurus. 



Fig. 1. Articulated caudal vertebrae 2 to 12, inclasive, of Ceratosaurus nasicornis Marsh. Type. No. 



4735, U.S. N.M. Viewed from the left side, os., row of dermal ossifications as found in position 



in the matrix, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11; 12; caudal vetebrae 2 to 12. (See p. 98.) 



2. Ventral view of same. Both figures are one-fourth nat. size. Drawn under the direction of 



Prof. 0. C. Marsh. (See p. 98.) 



Plate 23. 



Pelvis of Ceratosaurus. 



Pelvis and sacrum of Ceratosaurus nasicornis Marsh. Type. No. 4735, U.S. N.M. Viewed 

 from the left side, ac, acetabulum; is., ischium; p., pubis; p.f., pubic foramen; p.s., 22, 

 presacral vertebra 22; s., suture between pubis and ischium; s 5 , sacral five. One-fourth 

 nat. size. Drawn under direction of Prof. O. C. Marsh. (See p. 106.) 



Plate 24. 



Metatarsals of Ceratosaurus. 



Figs. 1-4. Metatarsals of left hind foot of Ceratosaurus nasicornis Marsh. Type. No. 4735, U.S. N.M, 

 1, anterior view; 2, lateral view, external side; 3, lateral view, internal side; 4, superior 

 view. II, III, IV, metatarsals 2, 3, and 4. All the figures are one-half nat. size. Drawn 

 under the direction of Prof. O. C. Marsh. (See p. 112.) 



