112 HISTORY OF BRITISH ZOOPHYTES. 
horny in colour and texture, consisting, as also the stem, 
of a single tube. The branches are erecto-patent. The 
branchlets are ringed at their origins. It is rather rare on 
the west coast of Scotland; but we got it on one occasion 
on an irony-like cinder dredged from the deep. 
Ellis, who discovered it on the Kentish shore nearly a 
hundred years ago, says—‘ Here the curious naturalist 
may plainly discover a polype branching out like the com- 
mon fresh-water Hydra, but strongly fortitied by nature to. 
support itself in its turbulent situation ; for he will observe 
that this is defended by a tough horny covering, and fixed 
by its base to solid bodies in the sea, to secure itself from 
the infinite number of enemies that every moment sur- 
round it.” 
Sir J. G. Dalyell remarks, that “ faint whorls, almost im- 
perceptible in the living product, indent the origin of the 
branch and the eatremity of the twigs. Chestnut-brown or 
umber is the predominant colour of the morganic parts; 
the hydra is very minute and reddish. The tentacula are 
susceptible of much elongation, when they become almost 
of cylindrical form.” The neck, he adds, is so flexible, 
that it is susceptible of complete recurvature, or looking 
behind, as we would say of other animals. He has wit- 
