THE NAUTILUS. ]:',<, 



than the ;ulults. A specimen withmu l.ir.ility, but probably from 

 ."Monterey, was in the collection of Mr. F. Button, now belonging to 

 his son, F. L Button. 



HOW UNIONES EMIGRATE. 



BY LORRAINE s. FRIERSON. 



In the June number of NAUTILUS, 1S91, is an article by Mr. C. T. 

 Simpson, on "The Means of Distribution of Unionida? in the South- 

 eastern United States," in which he says that he had often found U- 

 obesus Lea in dry places, where for nine mouths of the year they 

 must have been in a dormant condition. 



This Unio. which is no doubt a variety of U. declivis, U. si/mmet- 

 ricus, etc., 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 confra.yosa 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 Unionidce 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 Kissiinee, 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. 



Twice I have killed wild ducks with unios attached to their toes, 



