1052 Observations on the Muskrat. [ November, 
found the young of Unio occidens Lea, but not very common. In 
another locality where Unio lachrymosus Lea is the prevailing spe- 
cies, I found its shells forming the bulk of the refuse near musk- 
rat homes. In this same locality I found examples of Unio pli- 
catus LeS. and U. multiplicatus Lea, but they were not common. 
The young of heavier shells are to be found as commonly, in 
proportion to their abundance in the adjacent water, as are the 
remains of the more fragile species. I have estimated that about 
one-half the mollusks eaten are of the three species of Anodonta. 
I was surprised at the comparative abundance of the remains of 
Margaritana rugosa Lea in these piles of shells. This species is 
considered to be rather rare, but their shells are found as fre- 
quently there as are those of some of our more common species. 
From this fact I think the muskrat prefers the flesh of this spe- 
cies to that of others which might be more easily taken. I have, 
at times, found examples of living Unios among these heaps of 
shells; whether these had been brought there by the rats, or 
whether they had sought, of their own accord, a dwelling place 
`. among the remains of their dead ancestors I cannot say. The 
means by which the muskrat secures the body of a mussel has 
been frequently discussed of late. I think, from my observations, 
there are three ways in which these shells are opened. With 
many species I notice that the foot is very slowly withdrawn 
within the covering when the shell is handled. When such shells 
are taken it is very easy for the muskrat to insert its paws or long 
teeth between the valves and tear them asunder. The remains of 
some species show evidence of the cutting power of their enemy’s 
teeth, the edges are broken; when this is done it would be very 
easy for the muskrat to find a sufficient opening to secure the 
animal as in the preceding instance. By those two ways the more 
fragile shells may be opened; the heavier species which are occa- 
sionally found, nicely cleaned, about the opening of the muskrat’s 
home, could not be opened in this manner. I have on several 
occasions noticed these larger mussels lying on the bank of a 
_ stream near a muskrat hole, and within a few days they disap- 
~ peared. The only way in which I can see the muskrat could 
_ obtain the body of one of these larger mollusks is by leaving the 
animal out of the water until it becomes weak or until it dies, 
when = cps could be =i ona separated. Muskrats at times 
; of dea s. The remains of ducks, geese, 
