252 



INTRODUCTION TO ZOOLOGY 



CHAP. 



suspends itself from a leaf by means of a sticky secretion 

 given out by the tail. The larval skin splits at the head end, 

 and is pushed down and off the body. The 

 pupa form within swells to a blunt angular 

 body (Fig. 181, p) ; it is a deep yellow 

 colour at first, but it soon darkens. From 

 this pupa the perfect insect emerges in 

 about ten days. 



" The Cock -tail Beetle, or 



The Cock- Devil's Coach - horse (Ocypus 



^ * e ** les ofens),isoneof the "rove beetles," FIG 18 2. -One Larva 



(Staphy- . / ' of the Ladybird. 



linidae). which feed on insects, and are (Bn i arge d.) 

 frequently to be found roving 



about on footpaths and roads, perhaps making their way 



to new hunting grounds. This beetle is a dull black with 



a slight reddish tinge at the 

 end of the antennae. It has 

 peculiarly short elytra in 

 spite of its well - developed 

 membranous wings, which 

 have to be much crumpled up 

 to get them securely beneath 

 the elytra. In consequence 

 of the shortness of these, the 

 abdomen, which is very easily 

 movable, can be curled up 

 Fig. (183), and this is so con- 

 tinually done that the beetles 



have gained permanently the name of " cock- tails." The 



larva lives underground and is not often seen. 



FIG. 183. The Cock-tail Beetle 

 (Ocypus olens). 



e, The short elytra. 



Aquatic Beetles with Clubbed Antennae 

 (Aquatic Clavicorn Beetles). 



Type : The Silver Water Beetle (HydropUlus piceus). 



Some of the beetles with club-shaped antennae are 

 aquatic, and the largest of them is the Silver Water Beetle 

 (Fig. 184), a form which used to be fairly common round 

 London, but is now becoming scarce. It is a very dark green, 



