EXTINCT AMPHIBIA OF NORTH AMERICA 63 
broadly. The postorbital has not been detected. The postfrontal 
forms the greater part of the posterior boundary of the orbit. It is 
triangular and acuminate behind. It is bordered broadly by the 
parietal and supratemporal. ‘The squamosal element is also triangu- 
lar and it borders the parietal broadly. The supratemporal is evi- 
dently the largest element in the skull and on its posterior corner 
there is a flake of bone which may represent the quadrate though this 
is by no means certain. The quadrate has not been detected in 
any of the Carboniferous Microsauria so far studied although it is 
well developed in the Permian microsaurian, Diplocaulus. The 
epiotic is an elongate element in the transverse line of the skull. Its 
entire boundary is uncertain though a part of the sutures are present. 
The quadratojugal is elongate and lies posterior to the maxilla and 
with that element forms the lateral border of the skull. 
The canals of the lateral line system have not been detected on the 
skull. The sculpturing of the cranial elements consists of grooves 
and ridges which radiate from a center. They are more prominent 
on the parietals than elsewhere although the other skull elements 
present a strong sculpturing. 
There are also preserved on the slab of slate about ten millimeters 
posterior to the skull fragments of pectoral plates, probably repre- 
senting the clavicles and interclavicle. They are so badly fractured 
that the form cannot be determined. No limbs or vertebrae have 
been observed. 
MEASUREMENTS OF THE SKULL oF Tuditanus sculptilis MOoovIE 
mm 
engthot the skull immaedianwliines eet eee ee 20 
Widthrot-skull’at posterior border estimated. "2.220... 4.2... 24 
Diane teriOlgor Diba sees peers isan ee te te ee a ena ont at 3 
Wenmgtheoionbitee: Meee yc ty: x as rattan om arte eatraitart 205.08! te 4 
mterorbitalispacemerw teers ea ee Shier ce UNE ee eee 4 
Diametenotenoctrmlslesssthaine cw sapiens Tee ee tae I 
Pineal foramen about one-half mm in diameter. 
DICERATOSAURUS LAEVIS sp. nov. 
(Figs. 13, 14) 
The genus Diceratosaurus was established by Jaekel! for the 
reception of the species described by Cope as Cerater peton punctoline- 
t Neues Jahr. Mineral. 1903, p. 112. 
