CiiAP. in. CHELONIAN FAUN.^. 451c 



Mountains, bo3-on(l wliicli Turtlos do not occur. Its northern limit is as high as 

 the junction of the Yellowstone and the Missouri, Ijut does not touch the shores 

 of Lake Superior. Its southern limits extend to Tennessee, Arkansas, and Kansas. 

 The most characteristic species of this Fauna are Amyda mutica, Aspidonectes spinifer 

 and nurlialis, Chrysemjs marginata, Bellii and Nuttalii (oregonensis), Graptemys geo- 

 gra2)hica and LeSueurii, Trachemys Troostii and elegans, and Emys Meleagris. Ch. 

 marginata is limited to the region of the lakes ; but Ch. Bellii extends to the junc- 

 tion of the Missouri and Mississippi, while Ch. Nuttalii extends to the Upper Missouri. 

 Strange to say, Aspidonectes sjiinifer is among the species found furthest to the 

 north ; but Asp. nuchalis takes its place in Tennessee. Emj's Meleagris is most 

 common in the region of the great lakes. Cistudo virginea extends as far west 

 as the great lakes, and is replaced by Cistudo ornata further west and north. 

 Chelydra serpentina and Ozotheca odorata range as far west as any other Testudi- 

 nata, though the latter does not extend so far in a north-westerly direction as 

 Chelydra; this is also the case with Thyrosternum pennsylvanicum. Ozotheca 

 tristycha and Ptychemys hieroglyphica occur in the more southern parts. There 

 is something extraordinary in the distribution of Trachemys elegans, as it ranges 

 from the upper Missouri to the lower Rio Grande, while Trachemys Ti'oostii occupies 

 only the middle and more southern parts of the Avestern Fauna. Graptemys Le- 

 Sueurii is also found in a north-southerly direction, while Gr. geographica extends 

 from east to west in the more northern parts. The Testudiniua are as comi^letel^' 

 foreign to this Fauna as to the north-eastern. 



3d. The Soidhern Fauna. Its boundaries are easily traced. Beginning on the 

 Atlantic coast in the southern parts of North Carolina, it extends through South 

 Carolina, Georgia, Florida, Alabama, Mississippi, Arkansas, Louisiana, and northern 

 Texas. These limits coincide with the range of Ptychemys concinna and of Deiro- 

 chelys reticulata, and nearly also with that of Platypeltis ferox and Xerobates 

 carolinus, only that the two latter do not extend to North Carolina; Platypeltis 

 ferox does not even extend beyond Georgia. However, the most striking types 

 of this Fauna are Xeroljates carolinus and G^-pochel^'s lacertina. Besides Plat\peltis, 

 another Trionychid, A.spidonectes aspcr, occui'S in this latitude, but only in the more 

 westerly part of the Fauna, within which Goniochelys triquetra and Chrysemys 

 dorsalis are also limited ; Avhilst Trachemys seabra is only found on the Atlantic 

 side of Georgia and in the Carolinas. Ptychemys mobiliensis occurs only in the 

 States bordering on the Gulf of Mexico. Ozotheca odorata and Thyrosternum 

 pennsylvanicum belong also to the southern Fauna ; and so does Chel3-dra serpentina, 

 unless the southern Chelydra be a di.stinct species. (Comp. p. 417, note 2.) The 

 same may be said of Cistudo virginea, unless C. triunguis and major are also distinct 

 species. Malacoclemmys palustris is found everywhere along the sea-coast. 



