74 S. W. Williston. 
the line above. The frontals form but a small part of the upper 
orbital margin. The postfrontals are also small, forming the posterior 
upper margin of the orbit, and leaving but a small space of frontal 
margin between them and the prefrontals. The postorbitals are larger 
than the postfrontals, and also extend a little further back of the 
frontal suture. They form most of the hind border of the orbits, 
articulating with the squamosal behind and the jugal below. The 
jugals begin a httle in front of the middle of the orbit im an acute 
point between the lachrymals and the maxilla. They are broader 
just behind the orbit, where they articulate with the postorbitals 
above and the squamosal behind. Below the latter they extend as a 
rather narrow prolongation to or nearly to the hind angle of the 
skull, and to the outer extremity of the ‘‘epiotic’” bones. In the 
skull figured by Case and myself these posterior prolongations appear 
to be suturally separated from the broader part of the jugals in 
advance. <A careful examination of other specimens, however, reveals 
no suture here and leads me to the belief that the supposed suture is 
merely a fracture in the same place on each side, due doubtless to 
the fact of the subangular narrowing of the jugal at this place. 
If there be a distinct bone here I suppose that it must be the real 
quadratojugal, notwithstanding it has no articulation with the quad- 
rate. All the sutures I have so far described, save per- 
haps that between the nasal and lachrymal, and that between 
the postorbital and jugal, are decisively and clearly indicated in the 
different specimens, some of them conspicuously so, and they, more- 
over, agree in the different specimens, as long and patient examina- 
tions and careful measurements testify. Cope’s determinations of 
the cranial elements in Pariotichus and both Case’s and my own 
in the small skull of Labidosaurus recognize another suture dividing 
the so-called squamosal into two distinct elements, though we do not 
agree in the position of this suture. In the Labidosaurus skull fig- 
ured by myself there does appear to be a divisional line, indistinctly 
shown and agreeing on the two sides pretty well. Unfortunately in 
a half dozen other specimens showing this part of the cranial wall, 
some of them in the most perfect condition both above and below, 
I can find no trace of a divisional suture, even under the most careful 
