The Skull of Labidosaurus. Me, 
nearly complete, has been entirely separated from its articular rela- 
tions. The vomers, anterior part of the pterygoids, the palatines and 
the transverse bones are all in their normal positions. The nares, 
situated far in front, probably directly below the external orifices, 
are concealed by the mandibles, which are closed upon the maxillee ; 
nor is the suture distinguishing the vomers from the posterior ele- 
ments distinguishable. The narrow pterygopalatine shelf on each 
side shows, on the upper side at least, a suture between the palatines 
and pterygoids for a portion of the distance, though I can make out 
no suture separating the transverse bones, though such doubtless 
existed. The transverse bones are stout, forming a strong decliyity 
from the plane of the palatines, and they abut massively against the 
mandibles at least as far as their middle. In the middle, between 
the pterygoids, opposite and in front of the transverse bones there 
is a large ovate interpterygoidal space, in front of which the two 
pterygoids approach each other closely, though not touching. Pos- 
sibly in the living skull they actually met in the middle. In front of 
the basisphenoid the pterygoids curve inward so that they meet in 
the middle behind, leaving no space for a presphenoid or para- 
sphenoid, which is certainly wanting in this specimen at least, though 
distinctly present in a smaller skull, and recognized by Broili in 
this species, The pterygoids unite firmly with the basisphenoid by 
this inner sphenoid process. Along the margin of the interptery- 
goidal opening for nearly its whole extent, there is a row, possibly 
double in front, of small tubercular teeth; a patch of similar teeth 
is also present in front of the transverse declivity of the palatines, 
and yet another patch on the summit of each transverse bone. 
The posterior prolongations or quadrate processes of the ptery- 
goids, arising just back of the transverse bones from the base of the 
stout sphenoid processes, are long, thin, divergent, oblique plates of 
bone, extending back nearly to the hind margin of the skull, articulat- 
ing broadly but loosely with the plate of the quadrate as shown by the 
dotted lines in Plate III, Fig. 1. The inner border nearly touches 
the sides of the basisphenoid; the lower, thin and nearly straight 
border is continued to near the articular extremity of the quadrate. 
The basisphenoid is narrow in front, gradually widened behind, 
