EEVOLVING ANIMALS. 11 



ponds in question are not very pretty objects, the 

 reason for this anxiety 011 the part of naturalists 

 must he somewhat puzzling to the general public. 

 I propose to enlighten them on this point by de- 

 scribing some of the rare forms of life that would 

 thus be destroyed. 



The Conochilus volvooc, of which we print a 



FIG. 3. Conochilus volvox. 



sketch, is only found in a very few favoured places, 

 and that of the ponds referred to above is one of 

 them. The winter is the best season for getting 

 the creatures in their prime. I have always found 

 them in best condition and in greatest abundance 

 when the ice had to be broken to fish them up. 

 The usual method for collecting these and similar 



