LARVA OF GYRINUS. 59 



motion, like the legs of the centipede, but trail loosely 

 in the water. 



In due time the larva is full-fed, and it then, as do 

 many other aquatic creatures, leaves the water and 

 crawls up the stem of a water-plant, until it is several 

 inches above the surface. Having found a safe place, 

 it spins for itself a small grey cocoon, and there waits 

 until it has assumed its perfect state, when it breaks 

 through the walls of the cover, and again seeks the 

 water. 



There are ten English species of Gyrinus, some of 

 w r hich are rarer than others. The present species, 

 which is the most common, is about a quarter of an 

 inch in length, and blue-black in colour, with a red- 

 dish mouth. The elytra are greenish at the margins, 

 and become narrowed towards the apex. They are 

 very slightly striated and punctured. 



