166 FOSSIL TURTLES OF NORTH AMERICA. 
hind legs was much broader than it is in the case of Chelydra; and, as in the sea-turtles, there 
was a fontanel between the outer end of the hyoplastron and hypoplastron. There was also 
an extensive umbilical fontanel. The bones of the right and left sides were joined along the 
midline more like those of Chelydra than like those of the Chelonide. The epiplastron and 
entoplastron are figured by Wieland (Amer. Jour. Sci., XX, p. 336, figs. 7,8). The former are 
slender, the latter broad and lance-shaped. The xiphiplastron, as represented by that of 
T. stenopora (Case, op. cit., plate Ixxx., fig. 5), is slender and apposes digitations to its fellow. 
Cervical vertebra have been figured by Dr. Case (op. cit., plate Ixxxiu, figs. 2-4). These 
were more or less injured, being comprest laterally. A more complete series is in the Marsh 
collection at Yale, and these have been described by Dr. Wieland (Amer. Jour. Sci., XIv, 1902, 
p. 102). According to this author, the anterior 5 have their articular ends fashioned as in 
Chelydra and the great majority of turtles; that is, the first is composed of 4 bones; the 
centra of the second and third are convex in front and concave behind; that of the fourth is 
convex at both ends, as in turtles generally. The next four centra are concave at the anterior 
ends, convex at the posterior. Toxochelys differs from modern Cheloniide in not having the 
double concayities developt on the anterior end of the last cervical. The specimen furnishing 
these cervicals was not accompanied by the carapace, so that we can not estimate the length of 
Fic. 200.—T oxochelys latiremts. Front limb. .28. Specimen in Yale Univ. coll. 
a, head of humerus; 6, radial process; c, ulnar process; cen, centrale; e, ectepicondylar groove; g, entocondyle; 
hum, humerus; int, intermedium; /, pisiforme; rad, radius; ul, ulna; u/n, ulnare; I, I, etc., metacar- 
pals; 1, 2, 3, etc., distal carpal bones. Figure by Wieland. 
the neck relatively to the shell. The estimated length of the neck is 226 mm. The skull was 
114 mm. to the occipital condyle. 
Regarding the caudal vertebre little that is certain is known. It is not at all improbable 
that the vertebra which were described by Cope under the name Cynocercus incisus belong to 
Toxochelys. Two caudals are in a small collection of bones received from the University of 
Chicago, with the catalog number 230 and belonging to Toxochelys latiremts. The centrum 
of one is 18 mm. long. These vertebrae probably belonged toward the end of the tail. They 
are proccelous and possess short lateral processes. In general these vertebra resemble those 
of Cynocercus, but the cup is deeper and without sign of the perpendicular incision seen in 
Cynocercus, and the ball is more prominent. 
The coraco-scapular arch is more like that of the sea-turtles than like that of the snappers. 
The coracoid is long, narrow, and spatulate. A considerable neck is interposed between the 
glenoid fossa and the base of the proscapular process. 
The fore limb is best known from a specimen in the collection at Yale (fig. 200), which 
has been described by Dr. Wieland (Amer. Jour. Sci., X1v, 1902, p. 95, fig. 1). The humerus 
has also been figured by Dr. Case. Dr. Leidy also has figured the proximal end of the humerus 
of what is no doubt a member of this genus (Cont. Ext. Vert. Fauna West. Terrs., 1873, plate 
xxxvi, fig. 17). For a figure of the humerus of T. latiremts ‘see fig. 200, shown above. This 
specimen was accompanied by the lower jaw, and its identification thus made certain. 
The humerus of Toxochelys is regarded by Dr. Wieland as representing the form which 
he has called ‘‘thalassoid,”’ especially because he believes that the radial process has descended 
lower on the shaft than it is in Chelydra and that the ulnar and radial processes have moved 
