THREE POLYMELOUS FROGS. 
ROSWELL H. JOHNSON. 
Havine found three undescribed polymelous frogs in differ-. 
ent American museums, it occurred to me that the newly 
discovered method of skiagraphy might give an opportunity 
for the study of these cases without dissection, which is usually 
not permissible with museum abnormalities. The accompany- 
ing plates give the result of that work. 
Case I (Figs. 1, 5, 6, and 7), a Rana palmipes, which had not 
yet lost its tail, is from the collection of the Harvard Medical 
School. This specimen bears two supernumerary limbs arising 
from the right and left scapular regions. Of these the one on 
the left is inferior in size to the normal leg of that side and is 
entirely free from it. It is peculiarly devoid of pigment. In 
the skiagraph (Fig. 5) a small rod-shaped bone, answering to a 
clavicle or coracoid, is to be seen extending from the head of 
the humerus of the supernumerary leg on the left to the skull. 
The humerus extends past its joint with the radio-ulna in a 
cartilaginous projection. The formation of the hand is 
apparently normal The ulnar side is the more ventral and 
anterior The supernumerary leg of the right side is repre- 
sented by a mere stump, as some previous investigator has 
cut off most of the limb. This arises from the scapula, which 
is enlarged and misplaced on this side. 
Case II (Figs. 3, 4, 8, and 9) is a young Rana halecina Dum. 
and Bibr., which was collected by Mr. Carlos E. Cummings on 
vacant land in the city of Buffalo. It is now loaned to the 
Buffalo Society of Natural Sciences. Directly above the left 
hind leg arises a supernumerary leg with nearly normal mark- 
ings. In size this is but slightly less than the normal legs, the 
reduction being greatest in the phalanges. The head of the 
extra leg does not fit into an acetabulum, although it lies close 
to the position where its acetabulum would be. The left ilium 
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