THE ANNELIDA. 273 
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are purple, and terminate in a tuft of hairs or hooks ; the rest 
are yellow, and have no tufts. The branchial organs are arranged 
in six pairs—the foremost being the smallest, those near the tail 
the largest; their colour is a bright vermilion, which gives them 
the appearance of miniature coral branches. They have sixty to 
eighty tentacles rising out of the head, some of these being three 
times the length of the animal. These feelers are semi-transparent 
and yellow; frequently they are straight, occasionally spiral; all 
are hollow, their canals communicating with the general tube of 
the body. This profuse tentacle arrangement surrounds the whole 
animal’ with a capillary apparatus of the greatest delicacy. It is 
not a net, for each of the threads are distinct, but hangs about 
the annelid more like a silken cloud, or like that delicate mould 
which grows round decomposing fruits. In spite of their extreme 
tenuity, these fine feelers serve the annelid as means not only of 
supplying itself with food, but also of locomotion; and more 
than this, they are the defensive organs of the creature: for their 
surface is found to be covered with irritating vesicles, in the shape 
of small bottles with short necks; through the orifice passes a 
finely-pointed dart, which is probably traversed by a canal, 
through which the venom passes into the puncture. made by the 
point. 
If from the front part of the head of a terebella straws of a 
golden colour branch out, the annelid is an Amphitrite. The 
Fan Amphitrite (Amphitrite ventilabrum) is the prettiest found 
upon our coast. Its tube resembles a leathern sheath, and 
narrows gradually towards the tail. When the annelid is put 
into fresh water, for some moments it remains at rest, as if con- 
sidering the novelty of its position; soon little air-bubbles begin 
to escape from the tube, and then gradually appears the point of 
a streaked brush, composed of a multitude of feathery filaments 
of the brightest carmine. Gradually this plume expands into 
the fans, which join and form a circle like a peacock’s tail. Each 
filament is edged with fine barbs, arranged with perfect symmetry. 
The outer rim of the circle is of a reddish purple, shading off 
towards the centre to a golden yellow; five or six concentric 
curves traverse it; from this centre two triangular antennz issue, 
and above them two kinds of fleshy lobes, which may be compared 
