CRYPTOBRANCHUS, a genus of aquatic, but lung-breath ing tailed Amphibia, of the family Amphiumidae, characterized by a heavy, flattened build, a porous tuberculated skin, with a frilled fold along each side, short stout limbs with four fingers and five foes, and minute eyes without lids. Three species are known. One is a fossil (first described as that of a man) nearly related to the giant salamander of Japan and China, Crypto branclius maximus; the third is the hell-bender, mud-puppy or water-dog of North America, C. alleghaniensis. Both the fossil C. scheuchzeri and C. maximus grow to a length of over sf t. and are the largest Urodeles known, whilst C. alleghaniensis reaches i8in.
The eggs are laid in strings. They have been found in Japan, deposited in deep holes in the water, where they form large clumps (7o to 8o eggs) round which the female coils herself. The giant salamander has also bred in the Amsterdam zoologi cal gardens; the male took charge of the eggs for the ten weeks which elapsed before the release of the last larva. The larva on leaving the egg is about an inch long, provided with three branched external gills on each side, and mere rudiments of the limbs. The tail is used in swimming.