CRABS AND SHRIMPS. 



215 



like claws, combined with sucking-disks, while a slender 

 tube pierces the flesh and pumps up the vital juices. 

 Chondr acanthus, — which looks like a tiny doll dressed up 

 in a long petticoat, fantastically studded all over with 

 curved prickles, — clings to the gills of the John Dory by 

 means of its stout hooked foot-jaws, of which there are 

 three pairs. 



More strange still is the furniture of the Lerneopoda. 

 Here two long arms proceed from the thorax, which, 

 curving forward, meet at their tips in front of the head, 

 and uniting, carry a knob or button, which, being thrust 

 into the flesh of some miserable Shark or Salmon, main- 

 tains the needful hold for the robber's operations. A 

 similar creature (Achtheres), that infests our common Perch, 

 has a contrivance more elaborate still : the two arms unite 

 as before, but the knob at the point of junction now be- 

 comes a bell-shaped cupping-glass, beset within its rim with 

 an array of recurved hooks. Hanging by means of this 

 grappling-iron to the gums of the fish, it allows its body- 

 to swing without fear or danger of dislodgment, in spite 

 of the currents that are perpetually flowing through the 

 mouth and gills. In some very long and slender forms 

 constituting the family Penelladce, parasitic upon the 

 bodies of fishes, as the Sprat and Anchovy, the entire head 

 is plunged into the tissues of the prey, sometimes into the 

 eye, and is retained there by a curved prong which pro- 

 ceeds backward from each side of the head, exactly on the 

 principle of an anchor. An additional firmness is secured 

 to the Lernea, which infests the gills of the Cod, by the 

 prongs or flukes of the anchor being furnished with pro- 

 cesses shooting off irregularly on all sides, which, being 



