386 OSBORX AXD MOOK SAUROPODS OF COPE 



apart. They are first noted in tlie series in tlie articulation of dorsal 3 

 with dorsal 4. 



The diapophyses. especially in the anterior region, are long. The para- 

 pophyses are low in position in the first three dorsals, posterior to which 

 they are situated at a constant level. 



The dorsal centra are all of medium length, the anterior ones being 

 little longer than those nearer the sacrum. All of them are distinctly 

 opisthoccelotiS; contrasting with Apatosaurus and DipJodocus, in which 

 there is an abrupt change from strongly opisthocoeloiis anterior dorsal 

 centra to distinctly jDlatycceloiis centra farther back. 



The sacrnm is characterized by short spines and by a tendency toward 

 retardation in the inclusion of the vertebra immediately posterior to 

 dorsal 10 in the sacrum itself as a functional dorsosacral. 



The caudal series is distinguished from those of other sauropod genera 

 by its short spines with expanded summits, the relatively slight develop- 

 ment of the caudal ribs, and probably, but not certainly, by the absence 

 of a distal whip-lash. 



The scapula is large and massive. It is expanded at both ends. The 

 coracoid is subcircular in outhne ; it is more distinctly rotmded than that 

 of Apatosaurus, but less so than that of Diplodocus. 



The fore limb is not especially characteristic except in small details. 

 It resembles that of Apatosaurus. 



The ischium is one of the characteristic bones of the genus. In con- 

 trast with the rest of the skeleton, it is slender in form and has a long 

 shaft, differing in regard to the latter character from Apatosaurus and 

 Diplodocus. The pubis is very massive. It is somewhat more angular in 

 outline than that of Apatosaurus, and its median border involves a greater 

 degree of twisting. 



The vertebral formula is not definitely known. It is probably slightly 

 variable. As interpreted, it is: cervicals. 13: dorsals, 10: sacrum. 5 

 (dorsosacral -^ 3 primary sacrals -|- caudosacrals) ; caudals. 53. An- 

 other interpretation is: cervicals, 13: dorsals. 10; sacrum. 1 (3 primary 

 sacrals -J- caudosacral ) : caudals, 53. 



SYXOXTMY OF CAMARASAURUS COPE AXD MOROSAURUS MARSH 



In 1898 the S}Tionymy of Morosaurus Marsh with Camarasaurus Cope 

 was suofofested bv Osborn^ : in 1902 this view was favored bv Eiesfs® : in 



8 Henry Fairfield Osborn : Additional characters of the great herbivorous dinosaur, 

 Camarasaurus. Bull. Amer. Mus. Xat. Hist., vol. x. art. xii. June 4, 1898, pp. 219-2.38. 



9 Elmer S. Riggs : The fore legs and pectoral girdle of Morosaunis; with a note on the 

 genus Camniosaunts. Field Col. Mus. Pub. 63, Geol. Ser., vol. i. no. 10, October, 1901, 

 pp. 2T.5-2S1. pis. xl. xli. xlii. 



