Species of North American Tortoises. 113 



Length eight inches, height two inches and three-quarters. 



Inhabits the northern states in rivers and ponds : is fonder 

 of leaving the water than any other aquatic species, and will 

 remain uninjured in a dry place for some months. 



Mr. Say has erroneously supposed that this is the Testudo 

 scabra of Linnaeus : without entering into the consideration of 

 a question which has been so often discussed, and which has 

 long ago been determined by M. Latreille, I shall merely ob- 

 serve, that every thing combines to prove Mr. Say mis- 

 taken. The reader is referred to what has been written on 

 this subject by MM. Latreille and Daudin in their respective 

 works. 



9. Testudo palustris. 



Testa ovalis, depressa, carinata, nigra vel fusca, pallidiore 

 indistincte variata, striisque numerosis concentricis impressa : 

 vel laevis, grisea, lineis concentricis nigris in utroque scuto. 



Testudo centrata, Daudin. T. Terrapin, Schoepff. Eynys 

 centrata, Merrem. Salt-water Tarapin of the southern 

 states. 



Shell depressed, oval, carinate, emarginate behind, above 

 dusky or brown, indistinctly varied with paler, all the plates 

 marked with concentric striae. First vertebral plate four- 

 sided, the anterior face a little curved ; or pentagonal, the second, ' 

 third, fourth and fifth hexagonal, the three posterior faces of 

 the last much smaller than the others ; lateral plates large, 

 more or less hexagonal, the second and third pentagonal, the 

 fourth tetragonal, the sides antiparallel ; or sometimes pentago- 

 nal ; intermediate marginal plate oblong, rectangular, or trian- 

 gular, with the apex truncate, (he rest nearly quadrangular. 



