136 Field Columbian Museum — Geology, Vol. II. 



of the left femur. The largest of these (PL XLIII, Fig. 11), that evidently 

 immediately succeeding the sacrum, is flat at each end, and has neither 

 distinct processes nor zygapophyses, and only a small, low spine on 

 the posterior part; its width posteriorly is much less than that anteriorly. 

 The other three vertebrae are in a series, slightly separated from each 

 other, and are mere nodules of bone, without processes of any kind, 

 about four millimeters in length by three in width; the last one ends in 

 a conical point. From the tapering of the first, and the association of 

 the last three close by the side of the femur it seems very probable that 

 the tail was short and slender. 



measurements of vertebrae. 



Length, Width, Expanse, 

 mm. mm. mm. 



Atlanto-axis 14 



Third cervical 24 



Seventh cervical 21 



Eighth cervical (about) 9 



First dorsal 9 



Second dorsal 10 



Third dorsal 10 



Length of first five dorsals (about) 53 



Sixth dorsal 9 



Seventh dorsal . 9 



Eighth dorsal . 9 



Ninth dorsal 9 



Lumbar (tenth) 10 



First true sacral 9 



Second sacral 9 



Third sacral 7.5 



Fourth sacral 7 



Fifth sacral 6 



Sixth sacral 6 



First caudal, or caudo-sacral 7 



Distal caudals 4, 4, 4, 



RIBS. 



Thoracic. PL XLI, Fig. 1, r,r. There are apparently four pairs of 

 stout ribs arising from the first four dorsal vertebrae, the first three of 

 which, at least, are anchylosed to the centrum in the adult animal. They 

 were doubtless all attached to the four tubercles on each side of the 

 sternum. 



Beginning with the fifth dorsal, the ribs are single-headed, and are 

 very slender and delicate. Four pairs are discernible in the specimen, 

 and a fifth seems to be indicated by a fragment. The largest of these, 

 that apparently belonging with the fifth dorsal, is gently curved. It meas- 



