THE NAUTILUS. 139 
than the adults. A specimen without locality, but probably from 
Monterey, was in the collection of Mr. F. Button, now belonging to 
his son, F. L. Button. 
ee 
HOW UNIONES EMIGRATE. 
BY LORRAINE S. FRIERSON. 
In the June number of Naurrius, 1891, is an article by Mr. C. T. 
Simpson. on ‘The Means of Distribution of Unionidz in the South- 
eastern United States,” in which he says that he had often found U- 
obesus Lea in dry places, where for nine months of the year they 
must have been in a dormant cunditiun. 
This Unio, which is no doubt a variety of U. declivis, U. symmet- 
ricus, ete., is one that can stand such changes. I[ have obtained them 
in places where they must have spent half of their lives in such a dor- 
mant condition. On the other hand, some Anodontas and Margari- 
tana confragosa Say are so intolerant of heat that they are frequently 
killed by the sun’s rays while yet in water six inches deep. For the 
spread of these species of Unionidz some other means than those which 
would suffice for U. obesus must be employed. Should it be shown 
that embryonic unios become encysted in fish, of course the problem 
would be solved in large part. There is, however, a method em- 
ployed in nature which I have not seen mentioned, and which is to 
my mind a complete solution of the problem. Did any of my fellow 
Unio ‘‘cranks’’ ever catch Unio during the winter months by means 
of a long slender switch ? You go to a bed of mussels in clear water, 
and standing on the shore you gently poke the end of your switch 
into the gaping shell of the unsuspecting unio. As soon as it feels the 
stick it closes the shell tightly on it; then you gently pull the mussel 
out and put it in your game bag. 
Now suppose that this mollusk was an impregnated female, and that 
instead of a switch it was a wild duck’s toe, which was accidentally 
caught between the valves. What would happen? Why, that the 
duck would fly out of the Black Warrior river in Alabama, and finally 
alight in Lake Kissimee, Florida, and by this time either the unio 
would let go or the duck’s toe be cut off; and presto, a whole colony 
of unios is established. This is no fancy, but an observed fact, that is, 
so far as the transportation of unios is concerned. 
T wice I have killed wild ducks with unios attached to their toes, 
