270 PROCEEDINGS OF THE NATIONAL AIUSEUM. vol. xxxvi. 



(Jumnora {Camptosaurus) dispar Williston, Amer. Nat., XXIV, 1890, 



p. 472. 

 Camptosaurus dispar Zittel, Handbuch der Paleontologie, I, 1890, p. 756. 



fig. 666. 

 Camptosaurus dispar Furbringer, Jeuaische Zeitschr. f. Naturwiss., Jeua, 



XXXIV, 1900, p. 350. 

 Camptosaurus dispar Nopcsa, Foldtani Kozlouy, Budapest, XXXI, 1901, 



p. 210. 

 Camptosaurus dispar Hay, Bull. No. 179, IT. S. Geol. Surv., 1902, p. .501. 



Holotype. — No. 1877 consists of the atlas, axis, seven cervicals, first 

 dorsal, left scapula (lacking upper half of the blade), left coracoid 

 (also incomplete), two femora, tibia, fibula, astragulus, calcaneum, 

 nearly complete pes, and two manus. 



ParaUjpe. — No. 1877r^, so far as I am able to determine, consists 

 of a sacro-dorsal and four sacral vertebrae, all united by suture. 



Parutype. — No. 1878 consists of the left ilium, pubis, and ischium, 

 figured in the original description, together with a humerus, radius, 

 and ulna. 



The description calls for teeth and part at least of the lower jaws. 

 It may be Marsh refers here to a pair of incomplete jaws, No. 1888, 

 in the same collection, but this can not now be absolutely detennined. 



The above specimens were all collected by Mr. W. H. Reed from 

 Quarry No. 13, Jurassic (Morrison beds), 8 miles east of Como, 

 Wyoming, and are now preserved in the collection of the Yale Uni- 

 versity Museum. 



The original description is as follows : 



The presout genus is most nearly allied to Laosaurus, but diffei'S in several 

 points. The cervical vertebrje are all opisthoooelous, while those knovi^n in 

 Laosaurus are nearly plane. The pubis, moreover, is broad and thin in front 

 of the acetabulum, and directed well forward. It has a deep, well-marked 

 articular face for the support of the femur. The ischium is expanded at its 

 distal end, and has an extensive surface for union with its fellow. The femur 

 is longer than the tibia. 



This genus agrees with Laosaurus in one important character, namely, the 

 sacral vertebrae are not coossified. That this is not merely a character of 

 immaturity is shown by some of the other vertebrae in the type specimen, which 

 have their neural arches so completely united to the centra that the suture 

 is nearly or quite obliterated. To this character of the sacral vertebrae the 

 name of the present genus refers. With Laosaurus this genus forms a distinct 

 family, which may be called Laosauridw. 



The teeth in Camptonotus resemble those of Laosaurus, and are in a single 

 row in close-set sockets. The rami of the lower jaws were united in front 

 only by cartilage. There are nine cervical vertebne, all of which bear shoi-t 

 ribs, as in the Crocodiles. The dorsal vertebrne have their articular faces nearly 

 plane. The sacral vertebrae in all the known specimens are separate, and 

 their transverse processes are each supported by two centra. The chevrons 

 have their articular faces joined together. 



The fore limb is much reduced in size. There are five digits in the manus, 

 supported by nine carpal bones, three of which are united in one on the radial 

 side. The number of phalanges, beginning with the first digit, was 2, 3, 3, 3, 2. 



