662 PROCEEDINGS OF THE ACADEMY OF [Sept.j 



THE SPHAGNUM FROG OF NEW JERSEY-RANA VIRGATIPES Cope. 



BY HENRY W. FOWLER. 



On April 23, 1905, Mr. Thomas D. Keim and the writer, while 

 investigating the fauna of the Great Egg Harbor river, obtained a num- 

 ber of specimens of the interesting frog Rana virgatipes Cope, and were 

 fortunate enough to learn something of its habits. The species seems 

 to have been obtained on but two other occasions since it was first 

 found by Cope in October of 1891.^ Mr. Witmer Stone secured one on 

 Shoal Branch of Wading river, near Speedwell, N. J., June 20, 1901, 

 and on May 31, 1905, Mr. Paul Lorrilliere obtained one on a branch of 

 the Batsto river near White Horse, N. J. All the above specimens, as 

 well as Cope's types, are now in the collection of the Academy, making 

 a series of thirty- two examples. 



Our specimens were obtained at the mouth of Mare Run, the type 

 locality, and we noticed no other batrachia in the vicinity. 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 surround- 

 ings. They were shy and sank cpiickly out of sight among the aquatic 

 vegetation 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 w^as 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 sac 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 rap- 

 ping sound. These raps, or jerks, are about five or six in number. 

 The sound produced is peculiar in that it is difficult at times to detect 



» Amer. Naturalist, XXV, 1891, p. 1,017. 



