EXTINCT AMPHIBIA OF NORTH AMERICA 65 
in Fig. 14 is accurate. Asin Tuditanus tabulatus Cope the squamosal 
is excluded from the parietal. 
The form of the skull at once recalls that of the species D. punc- 
tolineatus Cope as figured by Jaekel. The orbits are located in nearly 
the same region of the skull and the sutures separating the cranial 
elements are quite similar in the 
anterior region of the skull. The 
species D. laevis is based on the 
divergent character of the horn- 
like protuberances which project 
from the supratemporals. ‘The 
horns of D. punctolineatus Cope 
are convergent. The present skull 
is also smaller and the parietals in 
D. laevis are much larger than in 
iiemriypes spectesa im ithe itype 
species also the pineal foramen is 
located well forward in the parietal 7 pos 
while in the present form the fora- F=frontal; J =jugal; M—maxilla; N= 
men is located well posterior. nasal; P=parietal; Pf—postfrontal ; 
Prf— prefrontal; Po=postorbital; Prs= 
supratemporal; Px=premaxilla; Qj= 
quadratojugal; So=supraoccipital; Sq = 
The orbits are circular and the squamosal. Xz. 
distance between them is equal to 
two-thirds of the dimension of the orbit. They are located well 
forward in the skull and are bounded laterally by the maxillaries. 
The parietal foramen is situated in the posterior third of the parietals. 
The nostrils have much the same character as in the type form. They 
are broadly oval. 
The premaxillae are elongate transversely being about twice as 
long as wide. They are identical in shape and relations with the 
same elements in D. punctolineatus Cope. ‘The nasal is nearly square 
and forms the interior boundary of the nostril. The frontal is elongate 
in the median length of the skull and it is acuminate posteriorly where 
the acumination is inclosed by the parietal and postfrontal. The 
parietals are by far the largest elements in the cranium. They form 
together an oval which is elongate in the longitudinal diameter of the 
Fic. 14.—The elements of the cranium 
The skull is almost rectangular. 
The nostrils are elongate ovals. 
