AMPHIUMIDAE 97 



mind that the differences between the genera of Amblystomatinae 

 are in reality very slight ; and the same applies to the sub- 

 families themselves. The presence or absence of teeth on the 

 parasphenoid, the possession of amphi- or opistho - coelous 

 vertebrae, do not mean much, and certainly do not forbid the 

 notion that all the recent Urodela are the offspring of one common 

 generalised stock which inhabited the northern portion of the 

 globe. Nothing is gained by hiding the solitary European species 

 of the essentially American genus Spelerpes under the name of 

 Geotriton. It is a Spelerpes in all characteristic points. Speaking 

 broadly, each of the three principal sub-families of Salamandridae 

 is characteristic of a sub-region ; the Salamandrinae of the Western 

 Palaearctic, the Plethodontinae of the American, while the Ambly- 

 stomatinae are chiefly Asiatic, at least so far as diversity of 

 genera is concerned. 



Fam. 1. Amphiumidae. Without gills in the perfect state. 

 The gill-clefts are in a vanishing stage, being either 'reduced to 

 one pair of small holes or being altogether absent. The maxillary 

 bones are present. Teeth occur in both jaws ; those of the 

 vomers form transverse rows. The vertebrae are amphicoelous. 

 The fore-limbs and hind-limbs are present, but small. The small 

 eyes are devoid of lids. 



This family is now represented by two genera, with only three 

 species, found in the United States and in Eastern Asia. 



Cryptobranchus. The limbs are functional, with four fingers 

 and five toes. The outer digits and the sides of the limbs are 

 bordered with folds of skin. The head and body are stout and 

 depressed; the tail is short, laterally compressed, and provided 

 with a fin. The skin is very glandular and slimy, and forms a 

 thick, irregularly-shaped fold along the side of the body. 



C. (Menopoma) alleghaniensis. The gill-clefts are normally 

 reduced to one pair, individually to the left cleft, the right 

 closing up. There are, however, four branchial arches and vessels. 

 The general colour is brown or grey above, sometimes with 

 darker patches, lighter below. The " Hellbender " reaches a 

 length of nearly 18 inches (about 46 cm.), is entirely aquatic, 

 and is apparently restricted to the rivers and streams of the 

 mountainous districts of the Eastern United States. It is very 

 voracious, living on worms and on fish, being much disliked by 

 the fishermen, as it takes the angler's bait, and destroys great 



VOL. VIII H 



