SOME CASES OF SALTATORY VARIATION. 
CARL H. EIGENMANN anD ULYSSES O. COX.1 
SOME specimens showing saltatory variation have been 
collected at various times for the museum of the Indiana 
University. It is the purpose of the present paper to place 
these on record. 
I. A remarkable case of meristic abnormality was collected 
near Harrodsburg, Ind. The specimen is a male of the com- 
mon frog, Rana pipiens Schreber, 54 mm. long, and shows the 
following characters (Fig. 1) : 
The forearm and hand of the right side are duplicated. 
The extra part arises just behind the normal arm and passes 
inward and forward to below the eye of the left side. It is 
I9 mm. long from its origin to the base of the fourth finger 
and 2 mm. in diameter. The normal right forearm is 12 mm. 
long and 5 mm. thick. Its striking and unique feature is the 
band of skin through which it passes, and which holds it as a 
sling. This band is well represented by the photograph, and 
is 4 mm. wide. The supplementary arm and wrist are so 
placed that the fourth finger occupies the posterior place. 
The second, third, and fourth fingers are as in the normal hand, 
but more slender. Separated from these there are, in the place 
of the first finger, two fingers, of which the first is the longer. 
The free portions of the five fingers measure respectively 4, 2 
34, 5, and 3mm. On the anterior margin of the base of the 
first finger there is a broad callosity. 
On the lower surface of the lower jaw, below the left eye, there 
are two tubercles, the posterior one the longer, measuring 13 mm. 
in height. There are no other indications of abnormalities. 
The variation here recorded may be classed with pathological 
abnormalities rather than with variations that lead to the 
mutation of species. | 
* 6 PRAN TE Sas Jfrom the Zoölogical Laboratory of the Indiana University, No. 38. 
33 
