1 72 SUCTORIAL CRUSTACEANS. 



are regularly driven to the beach to feed on them, and their bodies 

 are carted into the country to be used as manure. In China their 

 eggs are used as an article of food. 



SUCTORIAL CRUSTACEANS. ORDER SIPHONOSTOMATA.* 



The Suctorial Crustaceans have the mouth adapted for 

 sucking the juices that they obtain from the bodies of other 

 animals ; they are, therefore, essentially parasitic. They are met 

 with adherent to the skins and eyes of fishes, or sometimes to 

 their gills and the interior of their mouths. Their forms are ex- 

 tremely variable, and all appear to undergo several transforma- 

 tions in their progress from birth ta maturity. This group 

 embraces 



The Pycnogons,t strange-looking creatures, of small size, with very long 

 limbs, and their body divided into segments. They mostly take up their abode 

 under stones along the coast, or are found crawling upon sea-weed, or some- 

 times they hook themselves on to fishes and other marine animals. 



FIG. 174. PYCNOGON. FIG. 175. LERNEAX. 



The Fish-Lice, among which may be mentioned the Caligus Mtilleri, 

 found adhering to the gill-covers of the cod-fish, to which it holds on by claws 

 that terminate its fore-limbs, while with its beak it sucks the food upon which 

 it lives. All of these animals are parasitic, and are found attached to the gills 

 or other parts of fishes by means of a formidable apparatus of hooks and 

 suckers ; some species seem permanently fixed to their victims, but others arc 

 able to relax their hold at will and change their place. 



The Lerneans constitute a very extensive group remarkable for the sin- 

 gularity of their appearance. When young they resemble the young of Cyclops, 

 and are then provided with a frontal eye and natatory limbs, swimming with 

 facility ; but having undergone a certain number of moults, they cease to lead 

 an erratic life. The limbs now, no longer needed, become lost or waste away. 

 The eye generally disappears and the body assumes a strange form. The 

 female is at this time found fixed to some fish or other aquatic animal by 



* ai(f><i}v, siphon, a sucking-pipe ; 0-ro/u.a, stoma, a mouth. 

 f TTVKVOS, pycnos, thick; yovv, gony, the knee. 



