PARASITES AND MESSMATES 



219 



powerful biting jaws. Of C. borealis (Fig. 70), Mr. 

 Stebbing remarks that " it is a good swimmer, tena- 

 cious of life, a savage devourer of fish, and not to be 

 held in the human hand with impunity." The species 

 is not uncommon in British seas, and numerous indi- 

 viduals will sometimes 

 attack a Cod or other 

 large fish, perhaps after 

 it has been caught on a 

 hook, and gnaw their 

 way into its body, so 

 that when brought to 

 the surface the fish con- 

 sists of little more than 

 skin and bone. 



The little Eurydic 

 achatus, belonging to 

 the same subfamily, 

 Cirolaninse, is com- 

 monly taken in the 

 tow-net in sandy bays on our own coasts. 



FIG. 70 Cirolana borealis. 

 TWICE NATURAL SIZE. 

 Sars.) 



ABOUT 

 (After 



It is said 



sometimes to attack bathers, and to " nip most 

 unpleasantly." 



More definitely parasitic are the species of Mga 

 and allied genera, which have piercing and suctorial 

 mouth parts, and suck the blood of fish. They are 

 usually found adhering closely to the skin of their 

 victim by means of the strong hooked claws of the 

 anterior pairs of legs ; but they have not lost the 



