192 HISTORY OF BRITISH CRUSTACEA. 



creatures. Among these, and assisting to conceal and me- 

 tamorphose the plant, you may find a number of conical 

 tubes, varying from one-sixteenth to one-eighth of an inch 

 in length, made of a somewhat tough papery or leathery 

 substance, of a dusky colour, and of a rough surface. They 

 are stuck upon the fronds of the seaweed in all directions, 

 without any order, some laid along, others standing erect ; 

 sometimes singly, sometimes associated. From the open 

 extremity project two pairs of stout jointed antennse, both of 

 which are armed on their under edge with double rows of 

 spreading spines, like those of the interior antennae in Ca- 

 prella. These well-armed organs are affixed to a large oval 

 head, just in front of two black eyes, and are thrown about 

 incessantly, forcibly clutching at the water, or rather at 

 whatever may be passing in the water. The head ordinarily 

 just projects from the mouth of the tube sufficiently to see 

 what is going on without, and what prospect there is of 

 a successful throw ; but sometimes the creature protrudes 

 his first two pairs of feet. . . . The animal in its tube much 

 resembles the larva of the genus Phryganea, that anglers 

 value under the name of Caddis-worms. There, however, 

 the case is composed of minute pebbles, bits of shell, etc., 

 imbedded in a glutinous silk, with which the interior is 



