48 



Marvels of Pond-Life. 



covered ; but I have often^ and at an interval of months^ 

 seen the appearance of two, and am in some doubt 

 whether this was a deception, arising from the com- 

 pression employed, or was a genuine indication. 



Where this Rotifer occurs I have usually found it 

 plentiful, but unfortunately could obtain no constant 

 supplies after I had determined to make a special study 



A. Metopidia acuminata, as drawn by Mr. Gosse. B. Specimen 

 as seen and described in text. c. Mouth or gizzard. 



of the remarkable tail, which is much more complicated 

 than I have described. The Pterodina lived for some 

 time in captivity, and for a week or two I could obtain 

 them from my glass tank. They were likewise to be 

 found for some weeks in the same part of the pond, but 

 not all over it, until one day not a single specimen 

 could be discovered; notwithstanding a persevering search 



