128 TANAIS. 
of short triarticulated filaments, resembling the superior 
antenne in structure, and possibly performing similar 
functions. 
We have received specimens of this species from Ber- 
wick Bay, captured by our late friend Dr. George 
Johnston, also from Mr. David Robertson, of Glasgow ; 
as well as a considerable number of individuals captured 
by Mr. Loughrin, at Polperro, who informs us that they 
live gregariously below high-water mark, where they 
protect their small colony by retiring deeply within the 
fissures of the slaty rocks of the coast, where they collect 
together a mass of material of a ‘ leathery consistence,” 
behind or within which they take shelter. When dis- 
turbed they escape, and will spring to a considerable 
distance. This is probably done by bringing the head 
and tail together and suddenly straightening themselves. 
Among the several specimens sent to us by Mr. Ro- 
bertson, was one of a very slender form; so peculiar 
was it that we figured it under the impression that it was 
of a separate species from the present, and named it in 
the dredging list as 7. hirticaudatus.* But among the 
hundreds that we have had the opportunity of examining 
from several localities, we could identify many that 
were intermediate between the two extremes, and con- 
sider it not improbable that the slender form is but a 
specimen that had recently cast its skin. 
* Brit. Assoc. Rep, 1860, p. 225. 
sl 
