24 MAURICE G. MEHL 
rather well-defined pad of teeth, which in shape and size corresponds 
to a similar pad on the splenial. Measurements show that these 
two pads are exactly opposed posteriorly. Anteriorly, however, the 
lower pad apparently underlies the posterior part of the narial 
opening. The teeth of the palate group vary considerably in size 
and basal cross-section, apparently with no definite arrangement 
as to height or diameter. Most of the larger teeth, however, are 
disposed anteriorly although some of the smallest crowd closely 
on the posterior border of the nares. These palatine teeth are the 
same shortly conic, obtuse form as those of the lower dentition. 
They vary from 1.5 mm. to 3 mm. in height and from 1 mm. to 
4mm.in diameter. On the palatines one is able to make out about 
twenty teeth. The pterygoids are studded with irregularly placed, 
small, conical teeth, some fourteen of which are shown in the figure. 
These vary somewhat in size, though all are small, some being little 
more than mere points. Apparently all are hollow as are the other 
teeth. 
Mandible.—The nature of the lower jaw is given by E. C. Case 
in his revision of the Cotylosauria (p. 114). Fig. 2b shows a cross- 
section of the right ramus at the third tooth from the last in the 
dentary series. The suture above separating the dentary and the 
splenial is readily made out, as is that intersecting the broad lower 
surface of the ramus. It is the upper, inner element of the mand- 
ible that bears the pad of teeth referred to above. Clearly this is 
the splenial. Besides these sutures which are easily seen, it is 
possible that two other elements are shown as indicated by the 
dotted lines; one with an angular cross-section on the lower, infe- 
rior angle of the ramus, and a thin platelike one on the inferior sur- 
face. Immediately above the dentary, within the central cavity, 
lies a thin plate of bone that is apparently no part of the dentary 
or the element joining it. The central cavity is confluent with the 
large orifice immediately posterior to the splenial group of teeth, 
as shown in Fig. 2a. From the dentary foramen a well-marked 
suture runs up and forward to the inner, anterior margin of the 
Meckelian orifice. Further than this, one is unable to make out the 
sutures with any degree of certainty. Like the other dimensions 
of the specimen, those of the lower jaw are greater than in the type 
specimen as shown in the table. 
