OSTEOLOGY OF CARNIVOROUS DINOSAURS. 151 



Plate 13. 



Hind limbs, pelvis and sacrum of Antrodemus valens Leidy. No. 4734, TT.S.N.M. About 

 one-thirteenth nat. size. Viewed from the right side. Shown as mounted and exhibited 

 in the U. S. National Museum. The anterior end of the ilium has been incorrectly 

 restored as may be seen by comparing it with the left element shown in fig. 2, pi. 10, which 

 is complete. (Seep. 67.) 



Plate 14. 

 Femur of Antrodemus. 



Figs. 1-7. Left femur of Antrodemus valens Leidy. In Yale University Museum, a., anterior tro- 

 chanter; b., area for attachment of large muscle; h., head; ic., internal condyle; m.e., 

 medullary cavity; oc, outer or external condyle; tr., fourth trochanter. 1, external 

 view; 2, anterior view; 3, posterior view; 4, internal view; 5, proximal view; 6, 

 cross section of shaft; 7, distal view. All of the figures are one-fourth nat. size. Drawn 

 under the direction of Prof. 0. C. Marsh. (See p. 68.) 



Plate 15. 



Abdominal ribs of Antrodemus valens Leidy. No. 4734, U.S.N.M. Viewed from the 

 ventral side as found in the matrix. Less than one-half nat. size. (See p. 53.) 



Plate 16. 



Restorations of Antrodemus. 



Upper figure. Mounted skeleton of Antrodemus in the American Museum of Natural His- 

 tory, New York. No. 5753, about one-thirtieth natural size. This is the only mounted 

 skeleton of this animal. (See p. 56. j 



Lower figure. Restoration of Antrodemus (Allosaurus) by Chas. R. Knight. Based on the 

 mounted skeleton shown in figure above. Both figures after H. F. Osborn. Reproduced 

 here through the courtesy of the American Museum of Natural History. (See p. 56.) 



Plate 17. 



Skull of Ceratosaurus. 



Fig. 1. Skull and lower jaws of Ceratosaurus nasicornis Marsh, viewed from the right side. Type. No. 

 4735, U.S.N.M. About one-fourth nat. size. I, angular; 2, first antiorbital fenestra; 3, articu- 

 lar; 7, dentary; 10, hyoid? bone; 11, jugal; 13 maxillary; 14, maxillary depression; 15, ex- 

 ternal nares; 17, nasal horn; 19, orbit; 22, parietal; 24, postfrontal; 25, lachrymal; 26, pre- 

 maxillary; 27, postnarial foramen; 28, pterygoid + portion of quadrate; 30, quadrate; 

 31, quadratojugal; 33, squamosal; 34, surangular; (after Hay). (See p. 78.) 



2. Left side of same skull and lower jaws. About one-fourth nat. size. (See p. 78.) 



Plate 18. 



Restored skull of Ceratosaurus. 



Fig. 1. Top view of skull Ceratosaurus nasicornis Marsh. Type. Cat. No. 4735, U.S.N.M. (See p. 80.) 

 2. Skull and lower jaw of Ceratosaurus nasicornis Marsh. Type. Viewed from the right side. 

 No. 4735, U.S.N.M. an., angular; ar., articular; bo., occipital condyle; d., dentary; ex. 

 oc, exoccipital; /., frontal; /'., first antiorbital fenestra; j., jugal; la., lachrymal; lat. t.fen., 

 lateral temporal fenestra; mx., maxillary; n., nasal; n. h., nasal honcore; o., orbit: p., parie- 

 tal; p.ar., prearticular; pf., prefrontal; pmx., premaxillary; p.oc, paroccipital; po.f., 

 postfrontal 4-postorbital; pt., pterygoid; q. , quadrate; qj., quadratojugal; sa., surangular; 

 sq., squamosal; s.t.f., supratemporal fossa. Both figures one-fourth nat. size. (See p. 78.) 



