278 PROCEEDINGS OF THE NATIONAL MVSEVBI. vol. xxxvi. 



While the first digit in C. ampins is undoubtedly rudimentary, still 

 it is at once distinguished from the remnant of the first metatarsal in 

 Iguanodon by the heavy articular distal end of Metatarsal I, and the 

 j)resence of two distal j)h<^langes. The distal row of tarsals, as in C. 

 dispar^ consists of two elements (see Plate 17), although, com- 

 paratively speaking, somewhat reduced in size. 



PrinciiKil measnr-oncHts of Specimen, No. 1879, Yale Mnsenm. 



Digits. 



II. 



IV. 



Greatest length of metatarsals 



Greatest lengtla of tirst row phalanges 



Greatest length of second row phalanges. 

 Greatest length of third row phalanges. . . 

 Greatest length of fourth row phalanges . 



6G 

 43 



305 

 117 

 92 

 103 



345 

 124 

 87 

 60 



295 

 84 

 69 

 44 

 32 



° Incomplete. '' Missing. 



CAMPTOSAURUS MEDIUS Marsh. 



Cnmptosaurus medius Marsh, Auier. Jourii. Sci. (3), XLVIII, 1894, p. 85, 

 1)1. IV ; IGtli Ann. Itei). IT. S. (Jool. Sui v., 1894-95, Pt. 1, 1890, p. 190, 

 pi. Liii; Mou. (ieol. Siu-v., XXYII, 1897, p. 502, text figs. 58, 59. 



Cam2)to.sauru.<t medius Nopcsa, FCildtani K()zl(jiiy, Budapest, XXXI, 1901, 

 p. 210. 



Camptosaurus medius Hay, Bull. No. 179, U. S. Geol. Surv., 1902, p. 501. 



Holotype — Xo, 1880, Yale University Museum. This specimen was 

 collected by Mr. W. H. Reed from " Quarry 13 " in the Jurassic (Mor- 

 rison beds) of Albany County, AYyoming." It consists of a well-pre- 

 served disarticulated skull and jaws; 59 or more vertebra^, rej^resent- 

 ing all parts of the vertebral column, of which at least half have the 

 arches and spinous jjrooesses complete; tAvo humeri, two ulna^, one 

 radius, one femur, tibia and fibula, astragulus, calcaneum, left pes, 

 two ilia, ischium, i:)ubis, numerous ribs, and ossified tendons. 



The sj)ecies was never i^roperly defined by Marsh, the original de- 

 scription consisting" of the few lines which follow : 



There are at least two small species of the genus (C. medius and C. nanus, 

 noticed below). * * * f*. medius was about fifteen feet long. * * * The 

 skull, brain, and teeth of C. medius are shown on PI. IV. 



It is now known that the skull as figured '' was reconstructed, not 

 from the disarticulated elements of the holotype alone, but the nasal 

 region and the lower posterior section of the skidl and mandible were 

 drawn from No. 1887, Yale Museum (see Plates 7 and 8), a very 

 much larger individual which undoubtedly pertains to a distinct 



" In his Bibliography and Catalogue of Fossil Vertebrata of North America 

 Hay cites the occiu'rence of this species in Colorado. So far as known, it has 

 not been found outside of Wyoming. 



& IGth Ann. Rep. U. S. Geol. Surv., 1894-95, Pt. 1, 1896, pi, liii. 



