CRABS AND SHRIMPS. 
215 
like claws, combined, with sucking-disks, whilo a slender 
tube pierces the flesh and pumps up the vital juices. 
Chondracantlms , — 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 Lemeopoda. 
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 (Achthcres), that infests our common Perch,- 
has a contrivance more elaborate still : the two arms unite 
as before, birt 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 
