216 REPTILES OF MASSACHUSETTS. 



fourth, sixth, eighth, tenth, and twelfth plates are quadrilateral ; 

 the second, fifth, seventh, ninth, and eleventh, pentagonal ; the 

 edge of these marginal plates is sharp and entire. The ster- 

 num is composed of two valves, the posterior of which, the 

 larger, is oblong, rounded before, emarginated behind; both 

 valves are moveable, and when closed they shut the animal 

 entirely with the exception of his toes. The sternal plates, 

 twelve in number, are yellow, with large quadrangular dark 

 spots, occupying nearly one half of each plate ; the plates are 

 marked with concentric striae. 



The head is nearly black, with yellowish spots. The upper 

 jaw is of a dark brown color, with transverse yellowish lines ; 

 the lower jaw is of a bright yellow. The anterior extremities 

 are protected by large imbricated scales in front, with smaller 

 ones beneath, and granulations behind ; there are five fingers, 

 which are palmated, with nails. The posterior extremities 

 are larger than the anterior, of the same color, and, like them, 

 having scales and granulations ; these extremities are flattened 

 upon the leg and foot, with 5 toes ; the posterior only destitute 

 of a nail. Tail cylindrical, gradually tapering to a point. 



In regard to this species, Dr. Holbrook, in the third volume 

 of his Herpetology, which is just published, observes : " The 

 sole locality that can at this moment be assigned to the Emys 

 Blandingii, is the prairies in the state of Illinois and the territory 

 of Wisconsin, where they are said to be abundant. The only 

 specimen I have seen came from Fox river, a tributary of the 

 Illinois." 



Sphargis. Merrem. 



Generic characters. Body covered by a leathery skin, tuber- 

 cular in the young, perfectly smooth in the adult. Feet 

 without nails. 



