THE WOOD-BORING SHRIMP. 



627 



in recesses in the bank or under stones that form the bed of the stream, occasionally 

 darting out to seize some prey, and then making their way back again. Occasionally 

 they push themselves a yard or two up the rivulet, but are sure to come floating back 

 again before very long, allowing themselves to be passively swept along by the force of 

 the water as if they were dead, but starting suddenly into active exertion as soon as 

 they reach their former haunts. 



In the water this crustacean moves by a series of jerks, and mostly lies on its side, 

 though it of ten swims with its back uppermost, and frequently rotates as it passes along. 

 It is a voracious creature, feeding upon dead fishes or any similar carrion. It is fond 

 of the muddy parts of the stream, liking to conceal itself in the soft alluvium when fear- 

 ful of danger. The eggs of the female are kept for some time under the abdomen, and 

 the young remain in that situation until they have attained sufficient strength to shift 

 for themselves. 



The three remaining species are marine. At the lower right-hand corner of the 

 engraving is seen a creature lying on its back. This is the WOOD-BORING SHRIMP, a 



FRESH- WATER SHRIMP. (kuammrus pulex. 



E, F. MANTIS SHRIMP. Caprella lioearls. 



WHALE-LOUSE. Cfaau avails. 

 B, C. WOOD-BORING SHRIMP. CAe/ura terebrans. 



crustacean that nearly rivals the ship-worm itself in its destructive powers. The figure 

 is represented in the act of attacking a piece of timber, which it has already much 

 damaged. The Wood-boring Shrimp makes burrows into the wood, wherein it can con- 

 ceal itself, and at the same time feast upon the fragments, as is proved by the presence 

 of woody dust within its interior. Its tunnels are made in an oblique direction, not 

 very deeply sunk below the surface, so that after a while the action of the waves washes 

 away the thin shell and leaves a number of grooves on the surface. Below these, again, 

 the creature bores a fresh set of tunnels, which in their turn are washed away, so that 

 the timber is soon destroyed in successive grooved flakes. 



According to Mr. Allman, its habits can be very easily watched, as if it is merely 

 placed in a tumbler of sea- water, together with a piece of wood, it will forthwith proceed 

 to work and gnaw its way into the wood. The apparatus with which it works this 

 destruction is shown in fig. C, and is a kind of file or rasp which reduces the wood into 

 minute fragments. The figures are all enlarged, and that of the rasp is greatly magnified. 



In this creature the jaw feet are furnished with imperfect claws, and the tenth segment 

 from the head is curiously prolonged into a large and long spine. The great flattened 



