STEWART: NOTES ON SAURODON AND ALLIED SPECIES. 179 
similar to that of S. drveadheadii already described. The bone, just 
above the alveolar border, presents a somewhat shagreened appear- 
ance. Farther than this, there seems to be no characteristic 
markings upon the external surface. As the maxilla is firmly 
attached to the skull, the internal surface can not be examined. 
The premaxilla is plate-like, and nearly twice as deep as_ broad. 
The superior border is irregular and presents no condyle at this 
point. The external markings are very similar to those found in 
Saurocephalus dentatus, and the bone is directed more obliquely 
backward than in that form. The anterior border is directed 
sharply inward, giving the external surface of the bone a very 
convex appearance. This border is very rugose, probably for 
ligamentous union with its fellow of the opposite side. The 
alveolar border is very convex and has alveoli for twelve teeth, 
which are of about the same size as those on the maxillae. 
MEASUREMENTS OF MAXILLA AND PREMAXILLA. 
mni 
Maxilatyy eens thiObad Leola Onder sia csp fs oh ae ine. HSekcle sie Siete ga eens 82* 
dept ar palatine, condyleuac tia coon tisha a Duta ir fuer oN 33 
ss TUNA CH Lee EMI TM TseG setting eels Nemesis areas pc Sui Saab hh Ce ky 4 
RGeiiaTcn amen red Lest ep theme mi un ke Lostame manned Wh to. ounaun Soda ws Se) Sc ie 50 
a FRC ESD 3) Sia eg Te sd Gay lO aa Hin a ee eS There 30 
STH AT Te rICEADOLGEL Ay cha. aerta tee en tse Me; Vhgeay eaten 30 
In the mandible is found one of the chief characters that sepa- 
rate this genus from Sawrocephalus; instead of the upper and lower 
jaws terminating at about the same vertical plane as in all other 
members of the Sawrvodontidae, the mandible projects fully an inch 
beyond this point. The dentary is long and slender throughout, 
in Saurocephalus it is short and deep. This difference is well 
illustrated by comparing the types of Saurocephalus dentatus and 
Saurodon ferox; the maxilla of the first is considerably longer than 
that of the second, but with the dentaries, the reverse is the case. 
Only a small portion of the dentary can be seen, as most of the 
external and superior portions are hidden by the overlying maxillae.. 
The bones are irregular and shallow at the symphysis and seem to 
have given strong attachment for the predentary. The lower 
border is thin and sharp. Only twenty-seven millimeters of the 
alveolar border can be seen in the specimen upon which the teeth 
are small and twelve in number. At the base of each tooth is 
found the deep notch, for the nutrient vessels, so characteristic of 
this genus. As the articular portion does not seem to differ mate- 
rially from that of S. fevox, its description may be deferred. 
*Estimated. 
