Kingsley.] 
172 
[April 20 ; 
size, the left being three and the right three and a half inches 
long. The additional leg arises below and a little to the left of 
the vent and is about two and three quarters inches long. Not 
only in its origin but also in structure is it a leg of the left side. 
On an external examination, with the exception of its smaller 
size, it appears to be as perfect as either of its fellows. It flexes 
freely laterally but has only slight motion in the vertical plane. 
The anterior limbs are of the normal size and are perfect in their 
development. 
The iliac bones apj)ear to possess their usual form as do the 
ischiac portions of the pelvic girdle. The jmbes, however, are 
considerably modified. At the symphysis they are slightly ex- 
panded, forming a third concavity functionally comparable to the 
acetabula. Since the muscles which normally are attached to the 
symphysis pubis are thus driven from the usual attachment there 
is provided a slight enlargement on each side of the pubic bones 
for their origin. To save unnecessary circumlocution in the 
subsequent description, these processes will be called the false 
symphyses. Though not carefully examined, the bones of neither 
the normal nor the additional leg appear to present any anoma- 
lous features. 
The muscles of the right and left legs were arranged after the 
usual manner and possess no special peculiarities, except that those 
which ordinarily have their origin on the symphysis pubis in this 
case arise from the false symphyses. 
In the supernumerary limb, however, we find many points to 
note in the myology. The most prominent feature is the entire 
absence of many muscles. In the normal leg there are nineteen 
muscles (counting the triceps femoris as three) in the femoral 
region. In the additional leg; I could find but five in the same 
region. The identification of these was a matter of some difii- 
culty, but I believe four of them to be homologous with the vas- 
tus externus , vastus inter nus , rectus internus major and the 
semitendinosus ; the fifth may represent the obturatoriics. All 
of these appear superficially and I did not find any deeper 
ones. In determining; their homologies I found the insertion a 
more valuable character than any other. 
