AMPHIBIANS AND REPTILES. 123 
secured one on Shoal Branch of Wading River, near Speedwell, 
June 20th, 1901, and on May 31st, 1905, Mr. Paul Lorrilliere 
obtained 1 on a branch of the Batsto River near White Horse. 
All the above specimens, as well as Cope’s types, are now in the 
collection of the Academy, making a series of 32 examples. 
Our specimens were obtained at the mouth of Mare Run, the 
type locality, and we noticed no other amphibians in this vicinity. 
Associated in this locality were many examples of Chrysenvys 
picta and Chelopus guttatus, which were constantly bobbing about 
in the sphagnum. Enneacanthus obesus, Mesogouistius chetodon, 
Erimyzon sucetta oblongus and Notropis chalybeus abbotti were 
also abundant. The frogs’seemed to occur exclusively in the 
almost submerged masses of sphagnum which line the shores in 
many places, and often extend well out in the stream. Here the 
water is still and the animals rest more or less below, so that 
their dull colors harmonize well with the surroundings. ‘They 
were shy and sank quickly out of sight among the aquatic vege- 
tation on the approach of danger. In attempting to escape they 
would not jump or leap, and when caught in the dip-net moved 
about in a rather slow stupefied manner. They swam for short 
distances, but were usually able to find suitable shelter close at 
hand. The individuals obtained by Cope and Stone did not make 
any noise, but when we discovered ours the males were in full 
cry, which would seem to indicate that late April was the height 
of the nuptial season. The males are provided with distensible 
vocal vesicles, and when about to utter their call these sacs are 
inflated like little bladders till nearly spherical, and then by 
degrees the air is allowed to escape. This gives the sacs the 
appearance of collapsing by a series of jerks. As it is done 
quickly, each jerk at an interval of a second, the result is a sort 
of rapping sound. These ‘raps, or jerks, are about 5 or 6 in 
number. The sound produced is peculiar in that it is difficult at 
times to detect its source, and if the frog is close is quite startling. 
This is due not only to the suddenness, but also to the volume of 
sound. On one occasion an example which I captured had his 
vocal vesicles well inflated, and though they partly collapsed as 
I held him in my hand he did not utter any sound. The call bears 
