FOSSIL TURTLES OF NORTH AMERICA. 



above and the bridges rise considerably above the bottom of the plastron. The outline of the 

 carapace is somewhat pointed in front and furnisht behind with rather shallow scallops. 

 In the midline behind is an excavation about 80 mm. wide. As in the other carapace the bones 

 are rather thin. The specimen has the characteristics pointed out by Cope as distinguishing 

 his Baena hebraica, the presence of coarse grooves across the intercostal sutures and the high 

 marginal scutes over the bridges. The bones are thoroly co-ossified and no certain traces 

 can be seen of the suture between the nuchal and the preneural. The dermal sulci are mostly 

 distinct, but even these are obscure in the front of the carapace. The vertebrals are as in No. 

 5961. The marginal below the front of the first costal scute, probably the fourth, has a height 

 of about 35 mm.; two over the bridge have a height of 85 mm. 



The plastron presents no novel features, its sutures and sulci being obscure. 



The hinder portion of the skull is present, as well as the lower jaw. Its width behind is 

 90 mm. The temporal roof extended backward somewhat further than in No. 5961, but this 



con 



FIGS. 80 AND 81. Chisternon hebraicum. No. 

 5961 A.M. N.H. Fig.So, xf. Fig.8i,XJ. 



80. Skull from right side. Cond, occipital condyle; fr, 

 frontal; ju, jugal ; la, lacrirnal; mx, maxilla; 

 na t nasal ; pa, parietal ; pmx, premaxilla ; qj, 

 quadra-tojugal; qu, quadrate; si), squamosal. 



FIG. 82. Chisternon hebraicum. 

 XL No. 5904 A. M. N. H. 



End views of third, fourth, sixth, and 

 eighth cervical vertebrae. On the right 

 side the anterior ends; on the left, the 

 hinder ends. 



may be due to greater age. Over the brain-case the bone is 9 mm. thick. The lower jaw is 

 nearly complete. From the tip to the middle of a line joining the hinder ends of the rami the 

 distance is about 60 mm. The symphysis measured about 2O mm. The triturating surfaces 

 are concave in both directions; their width, 9 mm. The coronoid process stood 23 mm. above 

 the lower border of the bone. 



The neck had a length of 165 mm., about one-half of the length of the dorsal part of the 

 column (figs. 82, 83). The zygapophyses are high and not far removed from the midline. 

 There is a sharp crest on the lower midline of each centrum. The second and third are con- 

 vexo-concave; the fourth, biconcave; the fifth to the eighth, concavo-convex. The neural 

 arches appear to be co-ossified with the centra. Fig. 84 represents the scapula. 



The pelvis is shown in figs. 85 and 86. The ilia, the ischia, the pubes, and the epipubic 

 process are all solidly co-ossified. The expanded upper end of the ilium has a height of 52 mm. 

 and a width of 42 mm. The posterior articular end of the centrum of the second sacral 



