106 EMYS. 



Emys firmns. 



Prof. Cook submitted to my inspection a number of fragments of Turtle shells, 

 from the Green-sand formation of Tinton Falls, Monmouth County, N. J., among 

 which are several marginal plates of a carapace and fragments of sternal plates, 

 apparently belonging to the same individual. The osseous plates are as- remarkable 

 for their thickness as those of Emys crassns, from the Eocene sand of HordweU, 

 England, described by Prof. Owen.^ 



The specimens, also supposed to indicate a species of Emys, consist of fragments 

 of the third, fifth, sixth, and seventh right marginal plates, a portion of the sixth 

 and the nearly entire seventh left marginal plates of the carapace, and portions of 

 the right hyposternal and left hyosternal plates of the sternum. 



The exterior surface of the marginal plates is obscurely marked, as if impressed 

 by a piece of lace, but on some of the specimens the marking is obhterated. The 

 corresponding surface of the sternal plates is evidently smooth. Outlines of scutes 

 on the marginal plates are so obscurely indicated as not to be distinctly traceable. 

 The fragment of the hyposternal plate is crossed by a furrow defining the boundary 

 of the abdominal and femoral scutes, but the hyosternal plate presents only a short 

 interrupted furrow, which may be supposed to define the limits of the humeral and 

 abdominal scutes. 



The best preserved of the marginal plates, represented in Fig. 2, Plate XIX, the 

 sixth and seventh of the left side, have their outer surface moderately convex, and 

 sloping at an angle of nearly 45°. Their under part is strongly excavated to form 

 the upper boundary of the back opening of the shell. The basal margin of the 

 sixth plate is obtuse, but it becomes more acute as it extends along the seventh 

 plate. The two plates together measure along the curve of the basal margin five 

 inches and three-quarters. The width of the sixth plate about its middle is two 

 inches and a half; that of the seventh is two inches and three-quarters, and its 

 depth is three inches and three-quarters. 



As indicated in Fig. 3, Plate XIX, the left hyosternal (h) articulated by a trun- 

 cated angle with the right hyposternal plate (d) across the line of the median suture 

 of the sternum, which was quite irregular in its course. The strongly truncated 

 posterior angle of the right hyposternal plate would indicate that it also articulated 

 with the left xiphisternal plate across the median suture. The anterior sutural 

 border of the left hyosternal plate is sufficiently well preserved to indicate that the 

 entosternal plate measured two inches in transverse diameter. 



The left hyosternal plate along the line of the median suture measures two inches 

 and a half; its width in the same direction at the outer boundary of the entosternal 

 suture is three inches ; its thickness at the inner angle of the latter suture is over 

 an inch ; its thickness at the angle of articulation with the hyposternal plate is five- 

 eighths of an inch ; and Avhere thinnest, postero-extcrnally, the fragment is half 

 an inch. 



' British Fossil Keptilcs, p. 70, pi. 38. 



