lo Bulletin Wisconsin Natural History Society. [Vol. 9, Xos. 1-2. 



do so. The fact that they appeared in considerable numbers the 

 next spring shows that the pond was not necessary as a winter's 

 habitat. 



On March 31, 1909, the ice had melted about the edges of the 

 pond. Thorough search was made in the exposed water, and 

 every available cover along the shore line was overturned, but no 

 Ambystoma were found. The rocks on the hillside were still 

 frozen fast. 



On April 2, the ice had just disappeared from the pond, except 

 some very thin ice that had formed along the shore during the 

 night. Two specimens of A. jeifersonianum (male and female), 

 were found under stones at the water's edge. One female speci- 

 men of A. punctatum was found under a stone 100 feet from 

 water and about 10 feet above water level; this specimen was 

 almost rigid from cold. Only the stones on the slope at the foot 

 of the hill, adjacent to the pond, were now thawed out ; the steep 

 hillside, which presumably formed the main winter quarters of 

 the urodeles, was still frozen at the surface. A few days later, 

 when this hillside thawed out, specimens of both species were 

 found in greater numbers in all the localities mentioned, and 

 numerous spermatophores of A. punctatum (Smith '07 and '10) 

 appeared in the pond. The animals were evidently nocturnal in 

 their activities, since, in the daytime, only one specimen of each 

 species was ever found in the open water. 



Concerning the occurrence of a spring migration in A. 

 tigrinum I am in doubt. At Lake Forest specimens were found 

 in the open water as ! soon as the ice had melted from the edges of 

 the pond. The next day a trap, 60 ft. long, was constructed, con- 

 sisting of a zigzag paling of burlap extending along one side of the 

 pond ; pits were dug at the apex of each angle on the landward 

 side. Though this remained in place until late in the spring, no 

 Ambystoma were caught in it. If a spring migration occured at 

 all it must have been extremely early in the season. Hay ('91) 

 remarks: "In Indiana this species appears to pass the winter 

 hiding about the margins of ponds, or in some cases, away from 

 the water, under logs and such places. I have received specimens 

 taken under the ice, in company with A. microstomum, in January 

 and February." In the vicinity of the pond on Picnic Point, near 

 Madison, Wis., there is very little cover that would serve for 



