174 FOSSIL TURTLES OF NORTH AMERICA, 
has joined the hindermost suprapygal. Above and below, the pygal is broadly grooved from 
front to back. The most anterior peripheral is thin and narrow. The second is only slightly 
wider. The third has its inner face more developt and possesses a pit which received the 
extremity of the rib of the first costal plate. The inner, or costal, face of the succeeding periph- 
erals increases in breadth, until a section of the bone is a nearly equilateral triangle; then 
the face is reduced, so that at about the eighth the bone has grown quite thin and flat and 
relatively broad. Each peripheral, except the first and the orcad has a pit for the reception 
of a rib- end, until we come to the tenth. t 
Ordinarily in turtles the eighth costal plate sends its rib to the tenth peripheral, but in 
T oxochelys the eighth costal plate i is short and its rib does not extend beyond the border of the 
plate. As in Ghelyar a and most other turtles, there is no rib-end reaching the eleventh periph- 
eral. In the Cheloniide the rib of the eighth costal plate is turned Backward/to eis periph- 
eral, one of the more anterior peripherals not receiving a rib. However, Wieland represents 
the rib of the eighth costal plate as entering a pit in the eleventh peripheral. See fig. 235 of 
the present eg 
No. 1270 of the Kansas University museum furnishes a number of costal plates, a few 
neurals and the anterior suprapygal bone. ‘These are represented in Case’s figure already 
referred to. According to the present writer’s views, another peripheral ought to be inserted 
between the last one of that figure and the pygal; and there was almost certainly at least one 
suprapy gal behind the one eee represented. The neural which Dr. Case has called the ninth 
is certainly the eighth, since it has articulated with it the eighth costal. Resting partly on this 
neural and the fet suprapygal is a comprest tubercle at the base of which is a ican suture. 
The neural seen in front of the one just referred to is probably in its correct position; but the 
next one in front is certainly wrongly placed, being probably the fifth. The facet on the anterior 
end of the upper surface of the sixth has undoubtedly supported a tubercle similar to the one 
resting on the eighth neural. 
ae midline of the carapace of .T. ste nopora was traverst by a sharp and tuberculated 
keel, such as has been described as occurring in the specifically undetermined species (p. 164). 
As in that form, the more anterior tibeccles were connected with their underlying bones by 
open sutures. The elevation of the shell was probably about the same that we find in Chelydra. 
In the figure presented by Dr. Case, the costal plates are probably correctly placed ‘with 
reference to one another. As will be seen, there were large fontanels between the distal ends 
of the ribs. 
The plastron i is represented by fig. 220, reproduced from Dr. Case’s work so often quoted. 
Nothing is known regarding the entoplastron and epiplastron. There was a large umbilical 
foneanel. while there was, on each side, another fontanel bounded by the peripherals outwardly 
and by the hyoplastron and hy poplastron i in front and behind. The lateral digitations of the 
plastral bones did not enter into pits in the peripherals. The median digitations probably 
approacht closely those of the opposite side. A prominent longitudinal ridge on each side 
crost the hyoplastron and hypoplastron. 
Toxochelys elkader sp. nov. 
Figs. 221-223. 
Of the type of this species, No. 6137 of the American Museum of Natural History, there 
were secured the skull nearly complete; large portions, perhaps the whole, of the plastron; 
the shoulder-girdles; portions of the pelvis; aad apparently one or two peripherals. Excepting 
the skull, the parts have not yet been prepared for study. The specimen was found in the 
Niobrara beds, near Elkader, Logan County, Kansas, by Mtr. H. T. Martin, of the University 
of Kansas. 
The skull, like most specimens found in the Niobrara beds, is somewhat crusht. The 
length from the snout to the occipital condyle is 105 mm.; to the end of the supraoccipital 
spine, 143 mm. From the outside of one quadrate to that of the other is 101 mm. The outline 
of the skull, from a little in front of the quadrate, is nearly straight to the rather pointed snout. 
Both squamosals (fig. 221) are missing, but it 1s probable that each sent upward a process 
to the parietal. The latter bones are complete. The jugal extended nearly to the pedicel of the 
