266 



PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxvi. 



are long, pointed, and slightly curved longitudinally and laterally, 

 being deflected inward. They are somewhat depressed, except the 

 ungual of Digit I, which is higher than wide, and more sharply 

 pointed. They were undoubtedly incased in compressed pointed 

 claws, as indicated by a pair of lateral grooves on each ungual (see 

 fig. 35). The ungual of the second digit is the more robust of the 

 series. 



Measurements of the right hind foot of Specimen, Cat. No. Ji277, U.S.N.M. 



Digits. 



Greatest length of metatarsals 



Greatest antero-posterior diameter proximal end of metatarsals . 



Greatest transverse diameter of proximal end of metatarsals 



Greatest transverse diameter of distal end of metatarsals 



Greatest length 1st row phalanges 



Greatest length 2d row phalanges 



Greasest length 3d row phalanges 



Greatest length 4th row phalanges 



Greatest length 5th row phalanges 



mm. 



133 



15 



6 



26 



58 



a 59 



mm. 

 212 

 118 

 55 

 64 

 95 

 69 

 94 



III. IV 



mm. 



234 



106 



66 



76 



85 



53 



43 



a 90 



mm. 

 202 

 77 

 81 

 45 

 63 

 39 

 30 

 29 

 a 81 



" Measurements from other individuals of ahout same proportions as No. 4277. 

 THE GENUS CAMPTOSAURUS. 



In a paper published in December, 1879," Prof. O. C. Marsh pro- 

 posed the genus Cani'ptonotvH., and at the same time described two 

 species, G. dlspar and C. ampins., both from the Morrison beds (Atlan- 

 tosaurus beds of Marsh) of the Upper Jurassic. In the same article 

 he proposed the family Laosaurida3 to include the two genera Lao- 

 sourus and Camptonotus. 



In 1881,^ without comment, he proposed the family Camptonotida^, 

 under which the following genera were included: ('amptonotiis., 

 Laosaurus., Nanosaurus, and Diracodon. In 1882 '^ he briefl}^ defined 

 the family, including in it the European genus HypsUophodon^ 

 Diracodon being removed to the Stegosaurida'. 



The name C amptosaurus was proposed by Marsh in 1885 '^ to re- 

 place Camptonotus., preoccupied. 



Dollo,^ in 1888, gave an emended definition of the family, using 

 the older term Camptonotidse, under which he placed the two genera 

 Camptonotus and Tlypsilopliodon. To distinguish the former from 

 the latter, " Camptonotus " is defined as follows : " Two phalanges 

 in manus-digit-V. Preacetabular process of the ilium slight. No 

 rudiment of pes-digit-V." 



In 1889, Lydekker ^ referred three species to the genus Gamp- 

 tosaurus, C. leedsi, C. valdensis, and C. prestwichii, Seely's genus 



o Amer. Journ. Sci., XVIII, 1879, pp. 501-503. 



6 Idem, XXI, 1881, p. 423. 



<= Idem, XXIII, 1882, p. 84. 



^ Idem, XXIX, 1885, p. 169. 



ecompt. rend. Acad. Paris, CVI. 1888, pp. 775-777. 



f Quart. Journ. Geol. Soc. London, XLV, 1889, pp. 47, 48. 



4 



