Species of North American Tortoises. 1 19 



Iiiliabits from one end of the United States to the other, in 

 small clear streams, never in ponds or muddy water. The 

 variety a. differs very much in its appearance from the rest. 



12. Testudo muhlenbergii. 



Testa oblongo-ovalis, gibbosa, carinata, postice subdilatata 

 lateribus medio contractis, nigrescenti-fusca areohs lineisque 

 subradiantibus, flavis, striisque concentricis in utroque scuto ; 

 capitis latera macula magna aurantiaca. 



Schoepif. 132, tab. xxxi. Emys biguttata, Say, loco citato. 

 Chersine miililenl)erg2J^ Merrem. 



Shell gibbous, oblong-oval, carinate, a little wider and emar- 

 ginate behind, rather contracted on the sides near the middle, 

 dusky-brown with yellowish or reddish areolae and subradiating 

 lines (sometimes very indistinct,) and concentric striae on each 

 plate, which last in aged ones are only perceptible on the lateral 

 plates. First vertebral plate pentagonal, the second hexagonal 

 the lateral angles rounded, the third and fourth hexagonal, 

 the fifth heptagonal, the upper face rounded ; lateral plates, ex- 

 cept the last, which is generally smaller, subequal, the first four- 

 sided, the lower face rounded, the second and third pentagonal, 

 the fourth square ; intermediate marginal plate linear, very 

 small, the three next large, the four next small, the remainder 

 large and spreading, all of them oblong or square, with one or 

 more reddish spots on each. Sternum deeply emarginate be- 

 hind, very dark brown, varied with yellow or red, particularly 

 towards the middle ; scapular plates triangular, projecting at 

 the exterior angle, the rest quadrangular, the femoral pro- 

 jecting beyond the caudal at the inferior and exterior angle, all 

 of them marked with concentric striae : supplementary plates 



Vol. III. 16 



