548 FOSSIL TURTLES OF NORTH AMERICA. 
the outer ends of the costals (fig. 3 of plate 113), the pits arrange themselves more or less in 
rows parallel with the length of the animal. On an average there are about 8 pits in a line of 
25 mm. Near the middle line posteriorly some of the pits may have twice the average size, 
but this is unusual. Along most parts of the sutural borders of the costals there is a strip 
which is almost devoid of sculpture, except some striations at right angles with the suture. 
This condition is most conspicuous on the proximal halves of the costals. 
In a foot-note to the description of his Trronyx leucopotamicus Professor Cope has charac- 
terized a species, 7. punctiger, from the White River beds of Billings County, North Dakota. 
One of the characters which are given to distinguish the latter from the former is the presence 
of a pitless band of surface along the sutural borders of the costals. That is present in the 
specimen which has here been described as Platypeltis leucopotamica, but the writer can not 
on that account assign it to 7. punctiger. The latter species is said to have the ridges of the 
sculpture thickened and irregular and obscure on the outer ends of the costals. That is not 
true in the carapace above described. 7. punctiger is said to have the shell thicker than that of 
T. leucopotamicus. Cope’s type of the latter species has a thickness, thru the rib, of only 
6mm. The carapace here described from Nebraska has a thickness thru the ribs varying 
from g mm. to 11 mm., which is the thickness in the same regions of J. punctiger. It appears 
to the present writer that 7. punctiger is identical with 7. leucopotamicus; but more materials 
must be collected before certainty on this point can be obtained. 
It is not known to the writer where the type of 7. punctiger 1s. 
Professor Cope in his description of this species spoke of its close resemblance to Leidy’s 
Trionyx uintaénsis. Now that we have the complete carapaces of both species, it is seen that 
they are extremely different. 
Platypeltis ferox (Schneider). 
Trionyx ferox, SCHNEIDER, Schildkrote, 1783, p. 330; BouLENGER, Catalogue Chelonians, 1889, p. 259. 
Platy peltis jerox, Acassiz, Contrib. Nat. Hist. U. 5., 1, pt. ii, 1857, p- 401. 
In the Dr. Jarman collection of fossils obtained in Hillsboro County, Florida, and now the 
property of the Vanderbilt University, Nashville, Tennessee, there are several fragments of 
plastral and carapacial bones which the writer can not distinguish satisfactorily ae corres- 
ponding bones of the above species, now living in the rivers of Florida. With these bones come 
others which evidently belong to 2 or 3 undescribed species of the genus; but the fragments 
hardly justify the application of systematic names tothem. The beds furnishing these bones 
are supposed to belong to the Peace Creek formation. 
Dr. Friedrich Siebenrock (Sitzber. Acad. Wien, math.—naturw. Cl., cx1, 1902, p. 829) 
regards this species as identical with P. spinifera. In fact the two forms are very distinct. 
P. ferox has the carapace much more elongated and the sculpture is much coarser. Their 
geographical distribution is different also. 
THE END. 
