224 "The Ottawa Naturalist. [February 



northward is Mud puppy, but in the south it is known as Water- 

 dog" or D.'g^-fish. It has a wide distribution in eastern America, 

 including the great lakes system and those of the great rivers 

 southward. When full grown it is said to \ arj from eight inches 

 to two feet in length. In the Ottawa specimens of one foot in 

 length may probably be considered as above the average size. 

 The individual mentioned above was about five inches long, and, 

 althouiih alive when on exhibition, it had been so badly injured in 

 its forcible removal from its place of exit, that its days seemed to 

 be numbered. The mud-puppy is lizard-shaped, with four short 

 legs, on each of which there are four toes, and its tail is almost as 

 long as the body, and broad and flattened so as to form a power- 

 ful paddle for propelling the animal if it wants to leave the bottom. 

 At the base of the head on each side it has three tufts of large 

 bushy gills of a bright red colour, and t^o slits or branchial clefts. 

 These are the structures for maintaining respiration in the water, 

 but it has sufficient lung development to enable it to live for some 

 time when removed from its proper element It is apparently 

 largely nocturnal in its habits, lurking among stones and weeds 

 on the river bed, but may also be active in daylight, as some 

 years ago I saw several caught with hook and line by some boys 

 who were fishing on the Aylmer wharf. Its food consists of 

 worms, insects in their various stages, small crustaceans, tad- 

 poles, small fishes, frog.s and other small living forms upon which 

 it can seize ; probably it feeds upon dead animal substances as 

 well. Its presence in the water mains cannot injure the water 

 supply, except when one gets drawn into a service pipe and causes 

 a blockade. The animal belongs to the batrachians, which occupy 

 a position iiitermediate between the fishes and reptiles, and is 

 placed in the family Proteidae, the lowest group (of living forms) 

 in the class Batrachia. The majority of the batrachians undergo 

 metamorphoses, by which the gill-bearing young lose these organs 

 and develop lungs, and on maturity leave an aquatic tor a terres- 

 tial existence. The frog is a good example ; its young, the fami- 

 liar tadpole or poUywog, has external gills, or branchiae, and a 

 broad swimming tail, but gradually loses these appendages and 

 develops legs, which are remarkably serviceable both for land and 

 water. Our friend the mud-puppy, however, never outgrows the 



