ITS WEAPONS. 383 



standing erect ; sometimes singly, sometimes asso- 

 ciated. From the open extremity project two pairs 

 of stout jointed antennae, both of which are armed on 

 their under edge with double rows of spreading spines, 

 like those of the interior antennae in Caprella, These 

 well-armed organs are affixed to a large oval head just 

 in front of two black eyes, and are thrown about 

 incessantly, forcibly chitching at the water, or rather 

 at whatever may be passing in tbe water, just as 

 described above in the kindred and companion species. 

 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. These, especially the second pair, have a great 

 oval joint at the end, (See Plate XXII, fig. 13) with 

 a sort of knife-blade shutting on it, all formed on 

 the same model as in Caprella, but the next two 

 pairs of limbs have the middle joint curiously de- 

 veloped into a large projection on the upper side (Fig. 

 14). Three more pairs of legs follow, long, hooked 

 at the end, and directed backwards, and the body, 

 which is arched downwards like that of a shrimp, has 

 three pairs of swimming bristles, and terminates in 

 two styles. But all these latter details can be seen 

 only by opening tbe tube with a couple of needles, 

 and extracting the lurking inhabitant ; when you 

 may place him in the live-box of your microscope and 

 examine him at leisure (See fig. 12). 



The animal in its tube much resembles the larvae 

 of the genus I^hryyaiiea, that anglers value under the 

 name of Caddis-worms. There, however, the case is 



