BAENIDE. 79 
The course of the parieto-frontal suture is different from that of Chisternon hebraicum, since 
mesially it is placed further forward and runs outward and somewhat backward to the orbit. 
The upper surface of the skull appears to have been covered with horny scutes. 
All of the cervical vertebra are present, except the first. The whole series had a length of 
close to 100 mm., not quite one-third the length of the carapace. All have transverse processes. 
All have a sharp crest on the lower side of the centrum. These crests are so deep that they 
would have interfered greatly with any considerable flexure of the neck in a perpendicular 
plane. The second centrum is flat anteriorly, very concave posteriorly. The third is moder- 
ately convex in front, deeply concave behind. The fourth has the anterior end concave in the 
center, but the concavity is surrounded by a broad convex wall. The hinder end is shallowly 
concave. The fifth is rather deeply concave in front, flat behind. From the outside of one of 
the postzygapophy ses to that of the other of the vertebra is 13 mm. The centrum of the sixth 
cervical 1s concave in front. The form of the hinder end can not be observed. The front of 
the seventh is concave, the hinder end flat. The eighth is concave in front; the hinder end is 
quite convex, but small. The first dorsal has a large concavity to receive the convex surface 
of the eighth cervical. This concavity looks directly forw ard, as in the Pleurodira, not down- 
ward as in the Cryptodira. This is another indication that the head and neck were not 
retracted within the shell. In the hindermost of the cervicals the zy gapophyses stand high 
above the centra. Furthermore, the ends of the centra, especially when they are flat or 
convex, are considerably higher than wide. Both these conditions would be unfavorable to 
the flexure of the neck in a perpendicular plane. The postzygapophyses of the last cervical 
and the prezygapophyses of the first dorsal are short, not long and curved like those of the 
Cryptodira. On the other hand, the lateral motion of the neck could hardly have been so free 
as in the Pleurodira; and there was no projecting roof of the carapace under which the head 
could be concealed. We must conclude that these turtles could protect their heads hardly more 
than the sea-turtles. ; 
The ascending portion of the scapula (fig. 61) is long and slender; as is also the precoracoid 
process. The coracoids (fig. 62) are somewhat damaged; but it is evident that the median end 
was not greatly expanded, not so much as in some E mydidae. The humerus (figs. 63, 64) is 
67mm. long. The shaft is little bent. The distance from the outside of the radial process to the 
outside of the ulnar is 27 mm. The breadth of the distal end is 21 mm. The ectepicondylar 
foramen is situated g mm. above the condyle. The humerus is slightly longer in propor- 
tion to the length of the carapace than in Graptemys, but not so long as in Chelydra. The 
ulnar process doce not extend so far above the head as in Chelydra. The remainder of the 
fore limb is missing. 
The pelvis is badly crusht, but there appear to be no striking differences between it and that 
of Chisternon hebrarcum (figs. 85, 86). The ossified prepubic process is long, and it resembles 
that of the species just mentioned. The femur (figs. 65, 66) is 68 mm. long and moderately bent. 
In proportion to the length of the carapace the femur is shorter than that of Graptemys and 
still shorter than that OF Chelydra. The tibia and the fibula (fig. 66) are each 53 mm. long. 
The tarsal bones and some of the metatarsals are preserved. ana second metatarsal is 21.5 
mm. long. This appears to indicate a rather long foot. 
The tail was long. Eleven of the vertebra are preserved, having a length of 143 mm.; 
and there were evidently several more. So far as determinable, they were convexo-concave. All 
probably bore chevron bones. Some of the anterior caudals have, in the position of the neural 
spine, a rounded boss, as if for the support of a distinct bone, such as occurs on some of the 
caudals of Chelydra. 
The specimen figured and described by Cope (Vert. Tert. Form. West., p. 148, pl. xvii, 
figs. 1, 2) as Baéna arenosa is now in the American Museum of Natural History and has the 
catalog number 1112. Cope’s figures are one-fourth the size of nature and are inverted. His 
measurements are in some Cases erroneous. The carapace is 320 mm. long, instead of 450 mm. 
The carapace is somewhat crusht and its transverse diameter was nearer 260 mm.than 240 mm. 
The length of the plastron is 290 mm. The anterior lobe is 82 mm. long; the posterior lobe 
87mm. The width of the base of the anterior lobe is 102 mm.; that of the base of the posterio1 
lobe, 116 mm. The width of the anterior at the gulo-humeral sulci is 71 mm.; that_of the 
