298 



THE SEA SHORE 



It has been observed that the larvae live crowded together under 

 the protection of stones. 



The reader is probably acquainted with those fresh -water bugs 

 that are popularly known as ' boatmen ' on account of the oar-like 

 action of their long, fringed hind legs ; and although none of these 

 may be described as marine, yet certain species may often be seen 

 in salt and brackish water, living in company with creatures that 

 are decidedly inhabitants of the sea. 



We frequently meet with a pretty, slender-bodied insect, 

 measuring about half an inch in length without appendages, 

 creeping over the rocks in the sunshine, generally very near the 



FIG. 222. SEA SHORE INSECTS 

 1. jfpophilus. 2. Jfachilis maritima. 3. Isotoma maritima. 4. Cotlopa 



crevices in which they hide, and leaping from place to place when 

 disturbed. These are the Bristle-tails (Machilis), belonging to the 

 order Thysanura, the members of which, like the bugs, scarcely 

 undergo any metamorphoses. This insect (fig. 222) has long 

 antennae, and also a long, stiff, and elastic bristle extending 

 backwards from the tip of the abdomen ; and this bristle is the 

 means by which the creature leaps. Occasionally the machilis 

 may be found resting on the surface of the still water of a rock 

 pool, in which case its body is not wetted, its weight not being 

 sufficient to break the surface film of the water ; and, in fact, the 

 film is even sufficiently firm to enable the insect to leap on the 

 surface just as it would on a solid body. 



