MARINE ARTHROPODS 



303 



smoky tint of the elytra ; and the last species of the same genus 

 figured (B. quadriguttatum) may be known by the four conspicuous 

 spots on the deep violet-coloured outer wings. 



The same family contains an interesting little beetle Cillenium 

 laterale only about one-sixth of an inch in length, that lives 

 among the refuse washed on the beach, where it feeds on the 

 sandhoppers ; and although the latter are so much superior in size, 

 the beetle has no difficulty in holding and killing its prey, always 

 seizing it on the ventral side of the body, which is less protected 

 by the hardened skin. This species, which is of a copper colour, 

 does not confine its ravages to that portion of the beach which 

 is above high-water mark, but often allows itself to be covered 

 by the advancing tide, remaining submerged for a considerable 



FIG. 224. MARINE BEBTLEB 

 pys marinui. 2. Micralymma brevipcnne 



time. Another species Aepus (^Epys) marinus is even more 

 aquatic in its habits, for it searches out its prey among stones, 

 chiefly at the mouths of rivers, below high-water level, and is often 

 submerged for hours together. It is even provided with air-sacs 

 to enable it to withstand such prolonged submersions. 



There is another section of beetles which has elytra so short 

 that they cover only a small portion of the abdomen ; but although 

 so short, these elytra completely cover the long membranous wings, 

 which are folded up beneath them in a wonderfully compact 

 manner. The section referred to is termed Brachelytra, from the 

 feature just mentioned, and includes a few species that are more 

 or less marine in their habits. One of them Micralymma brevi- 

 penne lives under stones below high-water level, and apparently 



