920 
gret that before this specimen came into 
possession of the Museum, much damage 
was done to the relatively inconspicuous 
cartilages, in course of removal of the 
bones. Nevertheless Mr. Bourne, of Scott 
City, Kansas, who excavated the fossil, de- 
serves great credit for the skill and care 
with which the conspicuous parts were re- 
moved. 
The specimen reached the Museum ina 
series of large slabs of Kansas chalk and 
was worked out in such a manner that all 
the contours of the original slabs are pre- 
served and fitted together by their edges, 
as in the original bedding; therefore the 
great lizard with all its parts, excepting a 
few minor pieces, lies exactly as it was im- 
bedded. The original matrix surrounds 
practically all the bones, and can be distin- 
guished from the buff-colored outlying 
SCIENCE. 
' (N.S. Von. X. No. 260. 
to the left, together with the vertebre, as 
far back as the 6th dorsal. From the 7th 
to the 10th dorsals the vertebree are con- 
fused and displaced. The 11th dorsal to 29th 
caudal are horizontal with the transverse 
processes outspread and the spines crushed 
to the right and left. The remaining 
caudals, 30th—70th, lie upon the left side 
apparently in a natural position. The pel- 
vis and hind paddles have evidently shifted 
backwards in settling, so that the mooted 
question of the position of the sacral verte- 
bra cannot be positively settled by this 
specimen. 
This specimen agrees very closely in size 
with Cope’s cotype of 7. (Liodon) dyspelor, 
founded in 1871 at Fort Wallace, Kansas, 
and described by him in the ‘Cretaceous 
Vertebrata’ (p. 167). The skull agrees 
exactly in size with the fine one mounted in 
Fic. 1. Complete skeleton of Tylosaurus dyspelor in frame. 
plaster, by its somewhat darker shades. 
The whole is mounted upon a panel twenty- 
five feet long and permanently placed in a 
corridor which is to be devoted to marine 
reptiles. 
The animal lies outstretched upon its 
ventral surface, so that all the bones are 
exposed upon the dorsal or lateral surfaces, 
excepting the left humerus and ulna, 
which are overturned. The skull is crushed 
=|; nat. size. 
the Munich Museum, described by Merriam 
(1894, Taf. II.) as 7. proriger. Size is no 
criterion, or at best an uncertain criterion 
of a species, but Williston advances (1898, 
p- 175) no other satisfactory means of sepa- 
rating 7’. dyspelor from 7. proriger. Thirty- 
five feet is the length assigned by this au- 
thor to the largest Tylosaurs, a length con- 
siderably exceeding that of the present 
specimen. It is evident, however, that a 
