O. C. Marsh—New Tertiary Reptiles. 301 
Length of dorsal vertebra on lower surface,............. 13°6™"- 
BPIath OE CPs. neva Kids bes) {cued aieawt neers 9° 
Expanse of anterior zygapophyses,.......+-.s0+eeeeeees 16 
Length of two united sacral vertebree, eigiucecs ois 18°6 
Length of ‘lium, lise aden eas has ae ea ee 42°7 
The skeleton on which this description is mainly based was 
found in September last, at Grizzly Buttes, Wyoming, by Mr. 
. Quigley. Another ns eae was found at the same 
locality by Mr. G. G. Lobdell 
Thetiovasirvs crassus, Sp. NOV. 
A third and still larger species of the same genus is repre- 
sented in our Wyoming collections by a number of dorsal ver- 
tebree, and a few other less characteristic remains, all parts of 
one skeleton. The vertebree preserved differ con siderably from 
those of the preceding species, in being much more massive in 
proportion to their jong which is about the same as in 
ucidens. Those of the dorsal series have the inferior surface 
of the centrum aay straight niga meren ved and flat 
slightly concave eva ronsely The unarticular surface of t 
vertebree is everywhere irregularly striated The known re- 
mains of this species indicate a reptile about five feet in length. 
Measurements. 
Length of dorsal vertebra on lower surface,.........++++ 16.3 
Transverse diameter of articular cup,.....-.---++++e++-> 11:2 
MEVOOAG CIBINOLOr Ge BO occa scans 6 ak tate ae St 43° 
matin Giiwichie ns a cake cams vac 55 
Expanse of anterior zygapophyses,......--+--+eeee renee 
Expanse of posterior zy gapophyses, es uo eee mee eees 20°2 
The specimen on which the present species is based w 
found by the writer, last See in the Tertiary shale et 
Mery: s Fork, Wyoming. 
Thinosaurus grandis, sp. nov. 
A gigantic Lizard, the largest yet discovered in the Green 
River basin, and exceeding i in size any livi RPI is indi- 
cated by fragmentary portions of several individuals. These 
remains agree so nearly with those of the species above de- 
scribed that they may be referred, provisionally at least, to the 
genus Thinosaurus, The ve — so far as known, resemble 
in their proportions ene ae 
