159 



species here described, indicating a iK-ad oi- widci- ;iiliciilatii)ii of liiuncnis. 

 No limb-hones are preserved. 



The vertebra) are too miicli injnrud to be characteristic. One posterior 

 dorsal now has a compressed centrum, or, at least, not depressed. The infe- 

 rior face is convex transversely, and tliere is a slight concavity below each 

 diapophysis; but it is clear that il has been so modiOed by pressure as to 

 render its normal «hape a matter of uncertainty. 



Measiircmenfu. 



li. 



Piuictal, h'Uiitb 0.074 



Pariftiil, widtli bet wren tlic anlci ior iiids nf tlio crests 0.048 



Parietal, least widtli 0.022 



Frontal, intcrorbital width 0. Od:i 



Qn.-idrate, width above 0.020 



Quadrate, leiij;th from the pit to the proximal end 0. 023 



Sui angular, length of the lower e<lj;o 0. 01.'') 



Siiranguhir, depth in front of the cotjhis 0. liuO 



Snrangnlar, dejith at the end of the roronoid 0. 0")!j 



Posterior dorsal, length 0. O-lf.'i 



Kcripnla, proximal width 0. 051 



Tins species difi'cr.s from all ihor^c oi' 3Iomsaurus and Liodo)! \\) wiiich 

 tii(! form of the quadrate is known in th<; character of that bone. From 7^. 

 /■(Bvh: and L. congrops, in which that element is imknown, it difiens in the 

 stouter or less slender vertebrae; from L. proriger, in its much smaller size. 



Its size is a little less tiian the P. ktericus or L. mlidiis. It is dedicated 

 to Professor Mudge in reco^rnition of tiie valual)le results of his investigations 

 a:-r'8tate geologist of Kansas. 



PlATECARPUS TliCTULUS, Copo. 



Established on a number of cervical and dorsal vertebrae of smaller size 

 than those characteristic of the other species of the genus. The centra have 

 no', suffered from distortion under ])ressure. The articular surfaces arc de- 

 pressed transverse-elliptic in outline, with a slight superior excavation for 

 the neural canal. A well-marked constriction surrounds the ball. 



There is a rudimental zygosphen, in the form of an acute ridge, rising 

 from the inner basis of the zygapopliysis, and uniting with its fellow of the 

 other side, forming a j.roductionof the roof of the neural canal. 'I'he combined 

 keels become continuous with th(> anterior acute edge of t.iie neural spine. 

 Thus, the form is quite different from that seen in the previously-described 

 species, and constitutes a lower jrrade of rudiment. The fact that this zvgo- 



