64 



cave, and at each end of the lower side there is an obtuse hypapophysial 

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

 neural canals are relatively small, and the neurapophyses co-ossified. A third 

 vertel)ra, without arches, is similar in specific gravity, though without the 

 white surtace-layer of the others. It is appropriate in size and form to this 

 species, and is peculiar in its flat form, resembling the anterior dorsals of Ha- 

 drosmirus. 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. 



POLYONAX MORTUARIUS, Cope. 



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

 smooth ; the lower face is narrowed and probably keeled. 



Measiiremtnts. 



M. 



Anterior dorsal : 



Length of the ceutrnm 0. 048 



Elevation to the neural canal 0. 094 



Width 0.004 



Median dorsal: 



Length of tlic ccutriun 0. 0^<7 



Elevation to the neural canal 0. 117 



Width 0.08:i 



Posterior dorsal : 



Length of the- centrum 0. 00:i 



Elevation 0.104 



Width 0.08:! 



Diameter of tlie neural canal 0. 010 



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

 pophyses, and is probably a little affected by pressure. 



The linil)-bones cinl)raco portions of tibia, fibula, and some others not 

 yet determined. The portion of tibia is Irom the base of the cnemial crest, 

 so tliat one extremity is trilobate, the other transverse-oval. The former 

 outline indicates two posterior tuberosities. The bone is solid, and the 

 superficial layer for 3""" or less, is so dense and glistening as to resemble 

 ccmcntum. Portions referred to fibulfB have a subcrescentic section, with 

 narrowed width in one direction. Two fragments of shafts of long bones I 

 cannot determine, l)iit they may lielong to the pelvis. Tliey belong to opposite 

 sides; each is oval in section, and the diameter regularly contracts to one 

 end. One side is slightly convex in both directions ; the other is less con- 



