456 O. C. Marsh—Structure of Mosasauroid Reptiles. 
nt. 
The quadrate is large, with a stout elongated hook. The 
internal angle is nearly a right angle. The distal articular face 
is prominently convex, with its anterior margin but slightly 
inflected. There is a large tubercle on the inner margin of the 
hook opposite the meatal pit, but no articular button. The 
cervical and dorsal vertebree have transverse broadly oval ar- 
ticular faces, slightly emarginated above for the neural canal, 
The articular faces for attachment of the free hypapophyses ate 
sub-trilateral in outline, the smallest angle being in front. The 
rudimentary zygosphenal articulation is well marked. 
Measurements. ast 
Distance from end of snout to premaxillary suture, -- ---- 34°" 
Depth of maxillary at anterior nareal expanse, - --- ------ 39° 
Length of alveolar portion of dentary,----------------- 275° 
Width of basioccipital on condyle,-------------------- 55° 
Depth of hasioecipital,.......5 .. 2.2 Soo. ee ces 28° 
Rignith: of Guédratejn cis. SA Go. 2 en 93° 
Greatest diameter of distal articular face,-_-------------- 47° 
haunt diameter, ouls. oiodid.wieeuea. fo 2 cc ce 8 
ngth of posterior hook, é ic ~/2s..u0 sac auuses se abeers : 
Length of axis, with odontoid process,_---------------- 98° 
Tith: OF 0516: SONG, ieee si nade nn ee 66° 
Vertical diameter of articular ball of axis,-.------------ 27° 
Transverse diameter,_-..._...--- ‘ae 36". 
Length of centrum of first dorsal vertebra, ------------ 58 
wares Gameter of Hall... ss. owe nee 33° 
mueoeversc Giaatieter a ce nee 48° 
ee or are ee ee eee 141° 
Greatest diameter at proximal end,._.___-------------- 95" 
Greatest diameter at distal end,.........--:----------- 131 
MR RNs i i i ee 99° 
