Set 
of the temporal region, but very careful study of the original gelatine 
casts shows, in these specimens, evidence of the presence of both 
supra and infra-temporal arcades, the jugal bone being forked as in 
Sphenodon and in the Phytosauria. The cast of the top of the skull 
shows either a very small supra-temporal or a post-temporal fenestra. 
It was impossible to determine the presence of a pineal foramen. 
The occipital condyle, as shown in two specimens, is apparently 
entirely basioccipital and is rounded with a central depression. Unfor- 
tunately the palate is but poorly shown, and the internal nares 
cannot be definitely located, but they are probably almost directly 
below the external nares and rather widely separated by the vomers. 
The skull figured in Plate IV., fig. 8, shows tiwo rows of teeth near 
the middle line, probably borne on the prenarial portion of the 
vomer. 
The mandible is slightly longer than the skull, owing to a_post- 
arlicular extension. The symphysis ix about two-fifths of the total 
lenzht, and in one specimen the two rami are slightly pulled apart, 
showing that they were not coossified. Immediately anterior to the 
articular bone on the dorsal surface is a vacuity some 15"™. long. 
As to dentition, were not the specific name tenucdens preempted 
for its South African congener, it might well be applied to the present 
species, for the teeth, excepting the vomerine ones above mentioned, 
are exceedingly long and delicate, almost needle-like, round in section, 
and slightly curved. Some of them have a length of 14°". with 
a diameter of less than 1™. In one skull (Pl. IV., fig. 6) it is 
possible to count about 48 alveoli in each dentary bone ; in the upper 
jaw they seem tobe somewhat less numerous, about 38 on each side, 
but extend hackward at least to the orbit, and the alveolar border is 
about evenly divided between premaxillary and maxillary. Naturally 
the teeth toward the posterior end of the series are somewwat smaller. 
The extreme lateral direction of the teeth shown in figure 7 is dou- 
btless due in part to crushing; they prcbably were not very obliquely 
placed in life, but upper and lower teeth must certainly have inter. 
locked somewhat, and I regard it as unlikely that the animal was 
able to close its mouth entirely, a predicate from: which some other 
reptiles. suffered. 
The teeth were loosely placed in the relatively large alveoli and 
fell out readily during decomposition of the soft paris. I believe 
