370 CLASSIFICATIONS OF THE AMPHIBIA. 



Order I. — Abranchia. Gills wanting. 

 Family. Cceciliadce. 

 Order II. — Caducibranchia. Gills deciduous. 

 Tribe 1. Arcucadentia. Branchial arcs deciduous. 

 Families. Ranidce. Dactylethridce. Astrodactylidce. Salamandridce. 

 Tribe 2. Arcumanentia. Branchial arcs persistent. 

 Family. Menopomatidce. 

 Sub-class II.— DIPLOPNEUMENA. 

 Order III. — Manentibranchia. Gills permanent. 

 Families. Sirenidce. Proteidee. 

 It was my desire to have given fuller definitions of the 

 several sub-classes, orders, tribes, and families, and to have 

 added characters of all the genera, which I have here thought 

 right to adopt ; but professional occupations at present en- 

 tirely prevent the completion of that task. 



With respect however to the word Amphibia, used to de- 

 nominate this class of animals, its literal meaning signifies 

 the being able to live both on land and in water, — that is to 

 say, — the having at the same time two natures or faculties of 

 life ; namely, the faculty of life in the air, and the faculty of 

 life in the water. Now, the great vital principle, or original 

 spring of life, is respiration ; hence, whatever animal has the 

 faculty of respiring freely both in the atmosphere and in wa- 

 ter, can alone be strictly called Amphibious. Moreover, lungs 

 are — in the higher classes of animals — the only apparatus 

 that can perform the function of the former ; and gills are the 

 peculiar apparatus adapted to that of the latter. It is there- 

 fore evident, that all creatures not furnished with both lungs 

 and gills, are naturally disabled from ever enjoying real am- 

 phibiousness, or the twofold faculty of life ; and so, none of 

 the animals of this class, which belong to the Monopneume- 

 na, can receive the epithet of amphibious in its full and literal 

 sense; and of those belonging to the Diplop?ieumena 9 the 

 Amphiuma means, the Siren lacertina, and the Proteus an- 

 guinus, as far as we have yet learned, are alone entitled to it. 

 It is nevertheless more than very probable, that the greater 

 number (if not all) of the second sub-class, will hereafter be 

 proved to be strictly amphibious. 



Amongst other interpretations of this word, and in its re- 

 stricted but more common meaning, nearly the whole of the 

 monopneumenous animals may be called amphibious, 1 for 



1 In this sense are to be understood the animals which Cuvier names " les 

 Amphibies" consisting of the genera Phoca and Trichechus. In his Sys- 

 tem they form the third and last tribe of the Carnivora. 



