THE REPTILES OF OHIO 151 



Pseudemys scripta troostii (Holbrook) 

 Cumberland Terrapin 



Description. — A medium to large turtle attaining a carapace length of ten 

 inches. Largest adult Ohio specimen ( ? ), had a shell 9^/2 inches in length; 

 smallest specimen, 2 inches. Carapace rigid and covered with horny plates; 

 subovate, usually widest in the posterior half. Shell depressed (large females 

 more domelike) ; a vertebral ridge present in juveniles but absent in adults. 

 Costal and vertebral scutes normal, marginals 25; nuchal re'atively wide in 

 juveniles, narrower in adults. Carapace longitudinally rugose in large adults. 



Plastron large, immovably attached to the carapace and well covering the 

 soft parts; emarginate posteriorly, subtruncate anteriorly. Plastron about twice 

 as long as wide, omitting the lateral ends of the pectorals and abdominals 

 which are directed upward at an obtuse angle. 



Head moderate in size, snout rather blunt; upper jaw slightly notched, 

 lower jaw curved up in front. Feet well webbed, claws of forefeet in males 

 very long. Tail of medium size. Skin covered with scales which are largest 

 on the limbs. 



Specimens of this species undergo a complex change of pattern as they 

 grow older, this phenomenon being particularly marked in males. Small indi- 

 viduals are bright green with concentric yellowish and darker green markings 

 which may be U-shaped, parallel or convoluted on the costals and vertebrals, 

 and in the form of whorls on the upper and lower surfaces of the marginals. 

 Normally, on each scute of the plastron, there is a blotch consisting of two 

 black circular lines one within the other. Occasionally these markings on 

 adjacent scutes may be confluent or there may be extra or imperfect ones on 

 various parts of the plastron. The legs and head are streaked with yellow 

 and green. A bright red band on either side of the head extends backward 

 from the posterior corner of the eye. A yellow line extends backward from 

 a point just below the eye and may or may not meet a similar line on the 

 lower jaw. Another yellow line extends posteriorly from the symphysis of the 

 jaw and forks on the chin. Bright yellow lines are present on the tail. 



In all females and in young males the pattern is basically the same as the 

 above. In the older specimens, however, the markings on the carapace are 

 more differentiated and are yellow and olive, brown or black. On each costal 

 scute there is usually a conspicuous transverse band of yellow flanked by lines 

 of yellow and the darker color. The markings on the vertebrals are more or 

 less longitudinal. On the plastron the blotches tend to become uniformly dark. 



Adult males show decided tendencies toward melanism with a consequent 

 suppression of the normal pattern. Black transverse bands first appear on the 

 carapace (frequently on the sutures), these spreading and being joined by other 

 darker areas until the upper surface, and more especially posteriorly, ap- 

 proaches uniform blackness. At the same time black or brown areas appear 

 on the plastron, particularly along the median suture. These spread and be- 



