C0PE.1 PALEONTOLOGY CRETACEOUS PERIOD VERTEBRATA. 451 



measurements. 



M. 



Transverse diameter of condyles of femur 082 



Transverse diameter of shaft of femnr 053 



i of middle of condyles 054 



Diameter fore and aft< of side of coadyles 069 



( of shaft 038 



i greatest 102 



Diameter of head of tibia< fore and aft 096 



( transverse 060 



Diameter of shaft of tibia proximaiiy J £a™ft::".::".'.:".'.:; ;::::::::: :::: :o45 

 Diameter of distal end of tibia J £anTat. :::::::::: :::::: :::::: :::::: :::: -Jlo 



BemarJcs. — If the bones above described as pertaining to the hind 

 limb are really such, they are smaller as compared with the dorsal ver- 

 tebrae than in Hadrosaurus foulkei, and indicate an animal the size of a 

 horse. 



POLYOKAX, Cope. 



Char. gen. — A species considerably larger than the last, represented by 

 vertebrae and numerous fragments of limb-bones. The most characteristic 

 of the former are two probably from the posterior dorsal region, which 

 are somewhat distorted by pressure. The more anterior is shorter than 

 the other, and exhibits both articular faces slightly concave, the one more 

 so than the other. They are higher than wide, and the border is scol- 

 loped above for the capitular articulation for the rib. There are numerous 

 nutritious foramina, and some ligamentous pits on the articular surfaces. 

 The inferior face is rounded. In the longer vertebra, both faces are more 

 strongly concave, and at each end of the lower side there is an obtuse 

 hypopophysial tuberosity. The sides of the centra of both vertebrae are 

 concave. The neural canals are relatively small, and the neurapophyses 

 co-ossified. A third vertebra without arches is similar in specific gravity, 

 though without the white surface-layer of the others. It is hppropriate 

 in size and form to this species, and is peculiar in its flat forrn, resem- 

 bling the anterior dorsals of the Hadrosaurus. In this respect it is related 

 to the shorter vertebra of the two above described as the latter is to 

 the longer. The surface of the posterior articular face is damaged ; it 

 was not concave, and is now slightly convex ; the anterior is preserved, 

 and is concave. 



POLTONAX jMORTUARIUS, CopC. 



The articular faces are deeper than wide in the vertebrse ; the sides 

 are smooth 5 the lower faces narrowed and probably keeled. 



Measurements. 



M. 



Anterior dorsal, length of centrum 048 



Anterior dorsal, elevation to neural canal 094 



Anterior dorsal, width 094 



Median dorsal, length of centrum 057 



Median dorsal, elevation to neural canal 117 



Median dorsal, width 083 



Posterior dorsal, length of centrum 092 



Posterior dorsal, elevation 104 



Posterior dorsal, width ^ 083 



Posterior dorsal, diameter of neural canal 015 



The measurement of the neural canal is made near the base of the 

 neurapophyses, and is probably a little affected by pressure. 

 The limb-bones embrace i)ortions of tibia, fibula, and some others not 



