270 THE WORLD OF THE SEA. 
double purpose of glue and gilt. If a terebella be pulled out of 
its tube, its resistance is so strong that generally it is much hurt. 
Some of its tentacles are pulled off, and its rings staved in, but 
it seems little affected by the injuries, and at once sets to work 
to rebuild its house, with untiring energy, and exhibits no appear- 
ance of disappointment. The Zerebella textrix adopts a different 
plan. Instead of gathering about it foreign materials, and of these 
constructing its tube, it encloses itself in a fabric which it weaves 
like linen. This covering is very thin, and somewhat irregular ; 
TEREBELLA CONCHILEGA. 
the threads which compose it are so fine and transparent that 
they are almost invisible. It is a most complicated manufacture, 
for there are at least fifty threads as long as the little weaver 
himself. 
M. de Quatrefages has described a new and ravenous species, 
under the name of the Zerebella Emmalina. The body of this 
animal is long, and flattened like a ribbon. Its head is an azure 
blue, shading away through green to orange at its tail, which is 
remarkably thin. The under part of the body is a golden yellow. 
The articulations can scarcely be seen in the caudal region, 
becoming more distinct as the head is approached. Its feet issue 
from mammillary projections along its sides: the first fifteen pairs 
