208 ^ CRUSTACEA. 



selected as a support. At the moment the prawn has been thus 

 liberated from its old envelope, it rolls on the surface of the 

 ground perfectly helpless, for it is so soft that it does not possess 

 the power of supporting its own weight erect upon its feet, while the 

 beautifull}^ delicate antennae float fi-om its head like gossamer threads 

 in the water. In a short time, however, it plunges or springs from 

 place to place, stretches its webbed tail, and the large paddles of its 

 swimming apparatus, and soon retreats into some dark and sheltered 

 corner until its new shell is sufficiently hardened to allow of its 

 venturing forth. When the newly-coated shrimp first makes its exit 

 from its hiding-place its appearance is doubly beautiful ; and the 

 deportment of the little creature is altogether so bold and vain- 

 glorious, as though proud of its new vestm-e, that it cannot but 

 command tlie admii-ation it seems to seek. 



The Sluimp (Crangon). The connnon Shrimp {Crangon vulgaris) 

 does not exceed two inches in length, and is of a pale glaucous green 

 colour dotted with grey. During life the body is semi-transparent, 

 and so much resembles sea- water tljat the animal is distinguished 

 with difficulty. Its ordinary motion consists of leaps. It is abun- 

 dant in sandy places on the coast, and besides furnishing nutriment 

 to great niunbers of fishes, aquatic birds, &c., it is in great request 

 for the table. Shrimp -catching, or Shrimping as it is termed, aftbrds 

 constant employment on the flat sandy parts of our coast to boys 

 and women, who wade up to their knees pushing a sort of dredge-net 

 at the end of a long pole before them, but a more wholesale way of 

 collecting them is by means of sweep-nets, dragged over the fishing- 

 ground by men in boats. 



Brachyura,* or Crabs. These creatures are formed 

 for progression on land, or at least for creeping on 

 the bottom of the sea. The tail, the great instru- 

 ment of locomotion in the lobster, is in the crabs 

 reduced to a I'udiment, and the fin at its extremity 

 entirely obliterated. The chelce still continue to be 

 the most powerfully developed of tlie limbs, while 

 the legs, now become the principal locomotive agents, 

 are either terminated by simple points, as in those 

 species which arie most terrestrial in their habits, or 

 else, as in the s\yimming crabs, the posterior pair be- 

 come expanded into flattened oars, useful in natation. 



The habits of crabs are very various; some are 

 exclusively aquatic, and remain on the sands or 

 rocks at great depths in the sea; others inhabit 

 excavations formed in the soft coral reefs or bars on 

 certain coasts ; some spend their days altogether on 

 a shore, living in burrows or dens formed in a moist 



* ^paxvs, brachys, short ; oh pa, oura, a tail. 



