1894.] tone logy. 1045 
“The fifth pair of trunk legs is quite unique in form and disposi- 
tion: they arise quite close to the middle line of the body and high 
up, almost on the back ; they are short, being considerably less than 
the breadth of the carapace in length, aud are very slender and flex- 
ible; and they are so thickly fringed with shaggy hairs as to appear 
like feathers." 
This peculiar modification of the last pair of limbs is very unlike 
that of the corresponding legs in the notopodous or anomurous brachy- 
urans, and indicates that some special function may be assumed. The 
loss of geniculation and the straightness, the slenderness and flexibil- 
ity, and the dense hairylike covering must mean something. May it 
not be that the peculiarly modified limbs have been specialized for 
purposes of aérification of an increased vascular supply, and that they 
have become functionalized as branchie? Until some better hypoth- 
esis can be suggested or tested by histological examination, bold as it 
may seem, the explanation cannot be considered irrational. 
As has been already remarked, Retropluma has no close relationship 
with the forms compared with it or with any other known types, It. 
should, therefore, be regarded as the representative of an independent 
family— Retroplumide — especially characterized by the peculiarly 
modified fifth pair of feet, want of true orbits, and position of the 
antenne. For the present it may be retained in the superfamily or 
tribe Grapsoidea, on account of the reduced number of branchiz (“six 
on each side") and form of body. If, however, the illustrations and 
description of the mouth parts are correct, it must be widely removed. 
The only known species is Retropluma notopus. 
I cannot appreciate any “remarkably antique facies in the new 
erab." On the contrary, it Str to be a form excessively modified 
for deep sea life.—To. 
Note on the Occurrence of Hyla andersonii in New Jer- 
'sey.—About the middle of June, 1889, Mr. Louis M. Glackens and 
the writer were engaged in general biological studies along the Atsion 
and Batsto Creeks, in Atlantic and Burlington Counties, New Jersey. 
On the night of June 17th we stopped at Pleasant Mills. Shortly be- 
fore sundown a thunder storm arose, just previous to and during which 
the frogs became very noisy in a swampy thicket near by. 
'The note was an unfamiliar one and invited investigation, which re- 
sulted in the capture of two specimens of this handsome and rare spe- 
cies. The shrill quack-ack, which at the time was compared to the 
note of a frightened guinea fowl, and which is not unlike the call of a 
