Tortoises, especially the fresh-water kind, are very abundant; and the genera _Aromochelys_, _Chelydra_, _Terrapene_, and _Trionyx_, are nearly, if not quite, confined to this division of the region. _Amphibia._--Almost all the remarkable forms of Urodela, or tailed batrachians, peculiar to the region are found here only; such as _Siren_ and _Pseudobranchus_, constituting the family Sirenidæ; _Menobranchus_, allied to the _Proteus_ of Europe; _Amphiuma_, an eel-like creature with four rudimentary feet, constituting the family Amphiumidæ; _Notopthalmus_, _Desmognathus_, and _Menopoma_, belonging to the Salamandridæ; together with several other genera of wider range. Of Anura, or tail-less batrachians, there are no peculiar genera, but the Neotropical genus of toads, _Engystoma_, extends as far as South Carolina. _Fishes._--Owing to its possession of the Mississippi and the great lakes, almost all the peculiar forms of North American fishes are confined to this sub-region. Such are _Perca_, _Pileoma_, _Huro_, _Bryttus_, and _Pomotis_ (Percidæ); the families Aphredoderidæ and Percopsidæ; several genera of Cyprinodontidæ and Cyprinidæ; and the family Polydontidæ. _Islands of the Alleghany Sub-region._ _The Bermudas._--These islands, situated in the Atlantic, about 700 miles from the coast of Carolina, are chiefly interesting for the proof they afford of the power of a great variety of birds to cross so wide an extent of ocean. There are only 6 or 8 species of birds which are permanent residents on the islands, all common North American species; while no less than 140 species have been recorded as visiting them. Most of these are stragglers, many only noticed once; others appear frequently and in great numbers, but very few, perhaps not a dozen, come every year, and can be considered regular migrants. The permanent residents are, a greenlet (_Vireo noveboracensis)_, the catbird (_Galeoscoptes carolinensis_), the blue bird (_Sialia sialis_), the cardinal (_Cardinalis virginianus_), the American crow (_Corvus {135}americanus_), and the ground dove (_Chamæpelia passerina_). The most regular visitants are a kingfisher (_Ceryle alcyon_), the wood-wagtail (_Siurus noveboracensis_), the rice-bird (_Dolichonyx oryzivorus_), and a moorhen (_Gallinula galeata_). Besides the American species, four European birds have been taken at the Bermudas: _Saxicola oenanthe_, _Alauda arvensis_ (perhaps introduced), _Crex pratensis_, and _Scolopax gallinago_. A common American lizard, _Plestiodon longirostris_, is the only land reptile found on the islands. _IV. The Sub-Arctic or Canadian Sub-region._