SYSTEMATIC REVISION 



21 



An anterior caudal vertebra, field No. 252 Am. Mus. Nat. Hist, collection of 

 1908, of appropriate size to go with the type specimens, measures 182 mm. from 

 the base of the centrum to the top of the spine. The width across the transverse 

 processes to the point of origin of the ribs is 83 mm. 



Fig. 3. — Dorsal vertebra of D. maximus. x i- Type No. 4392 Am. Mus. 

 a, anterior view; b, posterior view. 



Genus DIASPARACTUS Case. 

 Diasparactus zenos Case. 

 Bull. Am. Mus. Nat. Hist., vol. xxvm, art. xvn, 1910, p. 174. 



Type: A few connected vertebrae from the posterior portion of the precaudal 

 series. No. 4797 Am. Mus. Nat. Hist. Cope Coll. From New Mexico. 



The vertebrae are the last presacrals and two sacrals. They are characterized by 

 the small size of the centra compared with the height and width of the neural arch 

 and zygapophyses. The transverse processes are so short that they do not extend 

 out from the centrum as far as the zygapophyses. The last perfect vertebrae of 

 the series, reckoned as the first sacral, shows a peculiar abnormal condition; the 

 transverse process of the right side is very small and there is no face for the attach- 

 ment of a rib, on the left side the transverse process is large but very short and there 

 is a large face for a sacral rib. An imperfect vertebra behind this one shows a 

 reverse of this condition; thisfts evidently a case of abnormal attachment of the pelvis. 



Fig. 4. — Vertebrae of Diasparactus ztnos. X J. Type No. 4797 Am. Mus. 

 a, lateral view of three posterior dorsals; t, posterior view of a vertebra. 



The first presacral has only a very short transverse process without any face for 

 the attachment of a rib. The second has a very short face on the transverse process; 

 this face is inclined forward as in Diadectes, but only very slightly so, and the upper 



