HABITS OF CRYPTOBRANCHUS ALLEGHENIENSIS. / 



fishermen who have speared by torchlight tell marvellous tales 

 of the number of these creatures they have seen, usually lying 

 quiet on the bottom when observed. According to Townsend 

 ('82), in the early summer, when the water is clear, hellbenders 

 are often seen on the bottom in considerable numbers ; in August 

 he found them only under rocks. Presumably his observations 

 were made by daylight. 



The cavity or cavern used as a dwelling-place has the rock for 

 its roof and the gravelly bed of the stream for its floor. In per- 

 haps the majority of cases, ready-made caverns are chosen as 

 homes, and these are reached by a natural opening. But the 

 cavity often bears evidence of having been in part hollowed out 

 by the animal, and is sometimes reached by a single burrow-like 

 entrance, with a little heap of freshly excavated gravel at its 

 mouth, on the downstream side of the rock. I have occasionally 

 seen the front limbs used to scratch and push away sand and 

 gravel, while the animal was forcing its way under a rock ; but 

 the burrowing habit is only slightly developed. It is interesting 

 to compare this beginning of the burrowing habit in Crypto- 

 branclms with its marked development in the closely related but 

 more terrestrial Aniphhima. 



There is a striking similarity between the habitat of the Amer- 

 ican Cryptobranchus and that of the giant salamander of Japan {C. 

 japonicus v. d. Hoeven, or Megalobatrachus maximus Schlegel), as 

 described by Ishikawa ('04) ; but in the case of the latter the 

 burrowing habit appears to be better developed. 



Cryptobranchus does not thrive except in cool and shallow run- 

 ning water. When a specimen is placed in a tank of quiet water, 

 it soon shows great uneasiness, swimming restlessly about as if 

 seeking means of escape, and coming frequently to the surface for 

 air. In a short time, as stated by Reese ('03), the stomach con- 

 tents are regurgitated. So long as kept in such an unfavorable 

 situation, it refuses food. 



Size. — Although during the season I handled more than a 

 hundred specimens, the largest adults of both sexes measured 

 only 53 cm. in length. Townsend ('82) records the capture of 

 some specimens 22 inches (56 cm.) long. The longest speci- 

 mens obtained by Reese ('04) measured 55 cm. By far the 



