PLUMATELLA. 381 



Hassall ; near Dublin, Prof. Allman ; Ayrshire, in a quarry- 

 pond on the under side of stones, and in lakes on the 

 under side of the leaf of Nymphaa alba (are they the same 

 species?), D. L. 



I have reserved this to the last, that I may close this 

 little work with an account of Plumatetta repens, which I 

 wrote for a periodical about ten years ago, when it had, to 

 me, the charm of novelty. 



It is called Plumatella, which is a diminutive of the 

 Latin word -signifying jo&me^; and the specific name repens 

 is given, because it is generally found creeping along the 

 under surface of stones and of leaves. It has been seldom 

 found in Scotland. When taken out of the water, it has 

 no beauty to attract the eye; but when replaced in the 

 water in such a position as that it can be contemplated with 

 the aid of a lens, what is beheld is both beautiful and won- 

 derful. When regarded with the naked eye, all that at 

 first is seen is the appearance of horny, leafless branches 

 proceeding from a centre, and setting out at short intervals 

 along the branches, and generally in pairs, what seem like 

 leaf-buds. In a little, however, there is the appearance of 

 life, and what was a naked leafless branch assumes a downy 

 appearance. The cause of this, by narrow inspection, can 



