EMYS. 107 



The jight hyposternal plate, along the median suture, is two inches and a half; 

 where widest, it measures in the same direction three inches and a quarter ; where 

 thickest, just back of the middle of the median suture, it is three- fourths of an 

 inch ; and where thinnest, externally, it is half an inch. 



Emys beatus. 



The museum of the Academy of Natural Sciences of Philadelphia contains 

 several plates and fragments of others of a carapace of a Turtle, from the Green 

 sand of Mullica Hill, Gloucester County, New Jersey, presented by William M. 

 Gabb. The specimens, represented in Figs. 1-3, Plate XVIII, consist of part of 

 the first vertebral plate, the entire third and fourth vertebral plates, portions of the 

 first left and second and third right costal plates, and the greater part of the first left 

 marginal plate. 



The fragment of the first vertebral plate (a) is the anterior half, and is crossed 

 near the broken edge by a groove, indicating the conjimction of the first and second 

 vertebral scutes. The lateral borders are sub-angularly convex ; the anterior border 

 is irregularly angular. The broken edge is three lines and a half thick, from which 

 position the plate thins away to the anterior border, where it measures one line and 

 a half thick. The breadth of the plate about its middle is fifteen lines, the esti- 

 mated length about thirty-four lines. The posterior portion of the plate, which is 

 lost, judging from the corresponding margins of the first and second costal plates, 

 appears to have been prolonged at its angles so as to join the antero-internal angles 

 of the second costal plates. 



The space occupied by the second vertebral plate is estimated to have been about 

 twenty lines long and fourteen lines broad at its widest part. The lateral borders 

 of the plate were subangularly convex ; the posterior border convex. 



The third and fourth vertebral plates (h, c), preserved entire, are elongated hexa- 

 gonal, or wide coffin-shaped. The anterior border is concave, the posterior is convex. 

 Of the lateral borders, Avhich are straight, in the third plate the anterior is scarcely 

 one-third the length of the posterior, and in the fourth plate the anterior is little 

 greater than one-third the length of the posterior. The third plate is crossed just 

 back of the middle by a groove, indicating the conjunction of the second and third 

 vertebral scutes. Its length is two inches, its breadth at the widest part in front is 

 seventeen lines, and its thickness five lines and a half. The length of the fourth 

 plate is twenty-two lines, its breadth at the fore part sixteen lines, and its thiclcness 

 is the same as the former. 



The fragment of the first left costal plate (cZ) is the vertebral portion, and is 

 grooved by the first and second vertebral scutes. It is thickest at the postero- 

 internal angle, where it measures four lines and a half and thins away to three lines, 

 two inches from the vertebral border. It appears not to have articulated with the 

 second vertebral plate, from which it was separated by the prolonged basal angle 

 of the preceding vertebral plate. Internally it presents a robust costal process for 

 articulation with the first vertebra of the carapace. 



The fragments of the second and third right costal plates are also vertebral 



