434 AMERICAN TESTUDINATA. Part H. 



Ptychemys hieroglyphica, A(/} Only known from the middle Western and South- 

 ern States. I have seen neither the young nor the eggs. I owe my specimens to 

 the kindness of Dr. Gessner, of Columbus, Georgia.' Dr. Holbrook describes it 

 from Tennessee. The upper jaw is emarginated, but smooth ; the lower jaw is 

 thinner and more feeble than in other species, and its edge also smooth. The 

 inner rows of tubercles in both jaws are more continuous. The whole body is 

 very flat, and the hind margin more deeply serrated than in the other species. 



Ptychemys decussata, A/.^ This species is not found within the borders of 

 the United States. It is a native of Cuba. But, as I had an opportunity of 

 comparing specimens forwarded to the Smithsonian Institution by Professor Poey 

 of Havana, I avail myself of this opportunity to state that it is a distinct 

 species of the genus Ptychemys, more nearly allied to Ptychemys concinna than 

 to any other. 



II. Trachemys, Aff. The chief difference between Trachemys and Ptychemys 

 consists in the horizontal alveolar surfaces of the jaws, which are much nar- 

 rower in Trachemys than in Ptychemys. The ridge of the upper jaw is less 

 prominent, low in front, and not tuberculated ; the lower jaw does not spread 

 horizontally, and has only a slight, smooth inner ridge. There is a notch in the 

 front of the upper jaw, but no lateral teeth ; the lower jaw is arched upwards, 

 and terminates in a hook. The marginal scales are separated by notches, and 

 the edges of the scales again are themselves notched. The tessellation of the 

 skin amounts to scales upon the neck, and upon the loose skin between the legs 

 and the shield ; but the form of the feet is the same as in Ptychemys. The 

 young have a slight, obtuse median keel, and their scales are finely gran- 

 ulated. Their color is very characteristic ; there are numerous longitudinal bands 

 upon the median scales, and transverse ones upon the costal scales, while the 

 marginal scales are ornamented with crescent shaped figures. As the animal grows, 

 the bauds become less and less niraierous, or disappear completely in old age. 

 At first smooth, they afterwards assume radiating ridges, up to the ■ seventh or 

 eighth year; and, finally, longitudinal ridges and rugosities prevail upon the scales. 

 (Compare p. 431, note 1.) 



Trachemys scabra, Af/.^ This species extends from North Carolina to Geor- 



^ First described by Dr. Holbrook, N. Am. Herp. tbe figures of the jaws published by A. Duraeril, Arch. 



p. Ill, pi. 17. In the figure of Dr. Holbrook, the Mas. vol. G, p. 231, pi. 15. 

 smallness of the head is somewhat exaggerated. ^ This species is generally known under the name 



^ This is the Emys decussata of Bell, figured by of Emys serrata (Holbr. N. Am. Herp., vol. 1, p. 49, 



Ramon de la Sagra, Cuba, Kept., pi. 1. pi. 5). It is also described as Testudo scripta, Schn., 



Emys Berardi, Dum. and Bibr., seems also to be- Emys scripta, Schw. But, since it is undoubtedly the 



long to this genus, judging from the description and Testudo scabra of Linnaius, I have restored its oldest 



