CHAPTER VIII 



THE MARINE INSECTA, ARACHNIDA, AND MYRIOPODA 



DOWN among the rock pools seems hardly a promising 

 hunting ground for the entomologist, and yet there are 

 not a few insects that live in the sea. 



To draw a clear line of demarcation between those that 

 are truly marine and those that occupy the strip of shore 

 just above high water, and sometimes are submerged, is 

 rather difficult ; but in this chapter I shall deal with those 

 that are nearly constantly submerged, and that are found 

 in the lowest parts of the littoral, treating of the others 

 in a separate chapter, " The Fauna of the Maritime 

 Zone," 



Commonest of those that I consider truly marine are 

 the little black " Spring-tails," representatives of which 

 family (Poduridce) are frequently seen among old books, 

 running a little way over a page and then springing several 

 inches. 



This marine form (Podura marina) is about an eighth 

 of an inch in length. It lives in the cleavage cracks 

 of rocks, from near high-tide mark to about half-tide level, 

 and is sometimes so abundant that colonies of it look 

 like patches of black velvet, sometimes four or five inches 

 across. 



There are several other species allied to these, that live 

 isolated, and are often seen even at the lowest tidal zone, 

 but they do not appear to have been studied. 



In the same situations viz, in cleavage cracks, and 



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