Lake Maxinkuckee, Physical and Biological Survey 621 



frequently in the former is probably due to the fact that our ob- 

 servations were more often directed to that lake. 



While pretty generally distributed throughout the lake, it is 

 naturally most often met with in relatively shallow water near 

 shore. It appears to prefer those locations where the bottom is 

 of muck, marl or other soft material covered with a growth of 

 short Chara. In such situations it makes considerable burrows 

 in the bed of the lake or sometimes merely under the Chara or 

 other covering. Here it rests when not moving about in search of 

 food or for other reasons. The burrow usually has two openings, 

 a few inches apart, one evidently for entrance the other for exit; 

 and the animal, when in the burrow, is often seen with its head 

 projecting from one of the openings as if watching for small fishes 

 or other food that may approach. Thrusting an oar or pole into 

 the burrow would frequently reveal the presence of the animal. 

 They seem to occupy these burrows singly, as in no instance were 

 two individuals found in the same hole. Whether they are more 

 prone to remain in their burrows during the day-time or night our 

 observations did not clearly disclose. Certain evidences, however, 

 which will be presented later in this account, indicate that this 

 curious batrachian is lai-gely nocturnal in habit, and the burrows, 

 if they could be examined with equal facility at night, would prob- 

 ably be found more frequently empty. 



While nearly all examples seen in the lake were in water one to 

 ten feet deep, they doubtless on occasion go out to greater depths, 

 evidenced by the frequency with which they are taken on hooks 

 of set-lines placed at a depth of 10 to 35 feet. They are doubtless 

 most abundant in water less than 15 feet deep, but extend out to 

 more than twice that depth in some numbers. It is probable that 

 their bathymetric distribution is practically coincident with that 

 of the plant covering of the lake bottom. 



That the species is largely nocturnal is indicated by a number 

 of habits which were observed. Frequently individuals were seen, 

 or were caught with seines, at night when they had come near 

 shore in shallow water evidently for the purpose of feeding on the 

 small fishes which also come into shallow water at night to feed. 

 Although large schools of the same species of fish were often 

 seen in the same places in the daytime water-dogs were rarely 

 noted and then usually in the winter and under the ice. Set-lines 

 were much more apt to have water-dogs on the hooks when exam- 

 ined in the morning than when inspected in the evening. 



That the species is, however, not wholly nocturnal is shown by 

 the fact that individuals are often seen in daytime moving about 



