134 BULLETIN 89, UNITED STATES NATIONAL MUSEUM. 



Plate 19. 

 Skull and sacral cavity of Stegosaurus. 



Fig. 1. Skull of Stegosaurus stenops Marsh. Viewed from the righl side. Type. Cat. No. 4934, 



U.S.N.M., about ^ nat. size. Reproduced from a photograph. See p. 27. 



2. Sacral cavity of Stegosaurus sp. Cat. No. 7380, U.S.N.M. j nat. size. Ventral view. 



a, anterior; e, sacral cavity; p, posterior end. See p. 56. 



Plate 20. 

 Right coracoid, humerus, ulnae, and radii of Stegosaurus. 



Fig. 1. Right coracoid of Stegosaurus stenops Marsh. Cat. No. 7411. U.S.N.M. J nat. size. Viewed 

 externally, a, anterior border; 6, glenoid fossa; c, coracoid foramen. See p. 67. 



2. Right humerus of Stegosaurus stenops Marsh. Cat. No. 4929, U.S.N.M. \ nat. size. Front 



view. /;, head; r, radial crest; s, supinator ridge. See p. 68. 



3. Right ulna of Stegosaurus. A, Cat. No. 4937, U.S.N.M. Type of Stegosaurus sulcatus Marsh. 



Adult: B, Cat. No. 7401, L T .S.N.M. Juvenile. Comparative side views to show the great 

 difference in the development of the olecranon process. Both £ nat. size. See p. 69. 



4. Right radii of Stegosaurus. A, Cat. No. 4937, U.S.N.M. Type of Stegosaurus sulcatus Marsh. 



Adult: B, Cat. No. 7401, U.S.N.M. Juvenile. Comparative front views. Both | nat. 



size. See p. 70. 



Plate 21. 



Scapula of Stegosaurus stenops, metacarpals of Stegosaurus sulcatus, and hind foot of Stegosaurus. 



Fig. 1. Right hind foot of Stegosaurus. sp. Cat. No. 4280, U.S.N.M. About -J- nat. size. Shown as found 

 in situ. I, II, III, digits one, two, and three. S, sesamoid. See p. 88. 



2. Metacarpals of Stegosaurus sulcatus Marsh. Cat. No. 4937, U.S.N.M. Type. ^ nat. size. 



Right fore foot, front new. 1, 2, 3, 4, and 5 metacarpals one to five. See p. 72. 



3. Left scapula of Stegosaurus stenops Marsh. Cat. No. 7371, U.S.N.M. \ nat. size Outer view. 



g, glenoid fossa. See p. 66. 



Plate 22. 



Skull of Ueloderma suspectum and dermal ossicles of Stegosaurus stenops Marsh . 



Fig. 1. Tuberculated upper surface of the skull of Ueloderma suspectum, the Gila monster, for com- 

 parison with the dermal tubercles of Stegosaurus. Aboutnat.size. After Osborn. See p. 91. 



2. Dermal ossicles of Stegosaurus stenops Marsh. Cat. No. 7615, U.S.N.M. i nat. size. External 



view. Shown as found in situ. See p. 91. 



3. Dermal ossicles of Stegosaurus stenops Marsh. Cat. No. 4934, U.S.N.M. T^pe. J nat. size. 



Internal side of ossicles. Portion of those shown in plates 2 and 4. See p. 91. 



Plate 23. 



Dermal plates of Stegosaurus stenops Marsh, and Stegosaurus sulcatus Marsh. 



t 

 Figs. 1, 2. and 3. Nuchal plates of Stegosaurus showing the change in shape and comparative sizes from the 

 skull posteriorly. (1) Cat. No. 4937. Belongs to the type of Stegosaurus suleatus Marsh; 

 (2) and (3) Cat. No 7615. All in the U. S. National Museum. All i nat. size. See p. 92. 



4. Posterior nuchal plate of Ste gosaurus stenops Marsh. Cat. No. 7584, U.S.N.M. ^nat.size. See 



plate 37, map of quarry 13, diagram 4, No. 211. This plate is correlated with No. 6 of No. 

 4934. See also plate 14. See p. 92. 



5. Dermal plate from region of shoulder of Stegosaurus stenops Marsh. Inner view. Cat. No. 



75S4, L'.S.N.M. | nat. size. See plate 37, map of quarry 13, diagram 4, No. 209. Thisplate 

 is correlated with No. 8 of No. 4934. See also plate 14. See p. 92. 



6. Dermal plate from sacral region of Stegosaurus stenops Marsh. Cat. No. 4714, U.S.N.M. -J nat. 



size. See plate 37, map of quarry 13, diagram 5, No. 95. This plate is correlated with 

 No. 13 of specimen No. 4934. See also plate 14. See p. 93. 



