PROTOSTEGIDZ. 193 
with the upper border of the jugal. The hinder end of the bone is broken away, so that the 
whole length can not be determined. The breadth of the bone, taken just Behind the process 
mentioned, is 105 mm. 
. No cs ae of a deipaine appear to have been preserved than that already mentioned. 
o parts of the premaxilla, nor vomer, nor parietals, n ipi y 
Bieaied with the bones above described. Se a ete eee 
Portions of the skull of this species were described by Case as cited in the synonymy. 
The supraoccipital is stated to resemble closely that of the Cheloniid, and to be quite different 
from that of Dermochelys. The basioccipital resembles that of the latter species, except that 
the portion belonging in the condyle is well ossified. The basisphenoid is said to resemble that 
of Dermochelys, but is not so large. Case pointed out that the hinder end of the pterygoid was 
as in Dermochelys, separated from the exoccipital by a lateral process of the basioccipital. The 
imperfectly preserved palatines indicated that the choanz were placed far forward. The vomer 
had no descending process to assist in underflooring the nasal passages. The quadratojugal 
and the squamosal were found to be as in the Cope_specimen, but to the present writer it 
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Fic. 248.—Protostega gigas. Skull, limb bones, and front of carapace. X4. 
No. 1421 Carnegie Museum, Pittsburg. 
Skull. fr, frontal; ju, jugal; mx, maxilla; nar, nares; orb, border of orbit; pa, parietal; prf, prefrontal; pmx, 
premaxilla; pof, postfrontal; gu, quadrate; qj, quadratojugal; sg, squamosal. 
Lower jaw. ang, angular; dart, dermarticular, or prearticular; den, dentary; hy, hyoid; sur, supraangular. 
Carapace. nu. p, part of nuchal; per. 1, per. 2, first and second peripherals; r.2, second rib. 
Fore limb. c, centrale; Aum, humerus; rad, radius; ul, ulna; ral?, radiale?; 7, intermedium; w/n, ulnare; pr, 
pisiforme; 1-5, carpals of second row; I-V, metacarpals. 
appears that Case has mistaken the upper border of the quadratojugal for the lower. The 
mandible was in perfect condition. The symphysis is represented as being equal to a very little 
more than one-third the whole length of a ramus. In addition to the bones found in the lower 
jaw of ordinary turtles Case states that the bone called by Baur,the presplenial, by Williston 
the true splenial, is present. 
The bones described and figured by Cope as metapodials (Cope’s plate xii, figs. 3, 4) are 
certainly not such, but epipodials. The original of his fig. 3 appears to be a tibia. The bone 
on the right of his fig. 4 may be a radius. The same bone in 4rchelon, as Wieland informs 
the writer, is now regarded by him as the ulna. 
No. 1421 of the Carnegie Museum, Pittsburg, was secured in the Niobrara Cretaceous, 
near Hackberry Creek, Gove County, Kansas. It furnishes the nearly complete skull; the 
humerus, radius, ulna, most of the carpal bones, and some phalanges of the right flipper; and 
the nuchal and first three right peripherals. These bones are yet imbedded in the matrix, so 
that only their upper surfaces are visible. The remains have been studied and described by 
Wieland, whose figure is here reproduced (fig. 248). The following measurements of the skull 
are taken from his paper: 
=) 
