(^ xis] 
V. On a new form of Corynoid Polypes. By Purzre Henry Gosse, Esq., F.R.S., A.L.S. 
Read December 2nd, 1856. 
ALTHOUGH every discovery of a new species of animal ought to be recorded with as 
much precision as can be commanded, it is not every such discovery that is worthy of 
being made the subject of a memoir presented to a learned body; but the form and 
manners of a creature which has lately fallen under my notice appear so anomalous, 
that I am induced to bring it under the notice of the Linnean Society. 
In the summer of 1855 I happened to have, in one of my marine aquaria, several 
specimens of a Sabella, which I believe to have been identical with the Amphitrite vesi- 
culosa of Montagu (Linnean Transactions, vol. xi. p. 19). The largest of these had been 
some time in my possession, and, probably owing to.the habitual stillness of the water 
in the vessel, not holding in suspension the particles of mud, that ordinarily enter into 
the composition of tlie tube, the latest-formed portion was composed of pure transparent 
chitine, without any perceptible earthy element. This clear terminal portion of the tube 
I perceived to be occupied by a curious parasite. About twenty bodies having a most 
ludicrously-close resemblance to the human figure, and as closely imitating certain 
human motions, were standing erect around the mouth of the tube, when the Sabella 
had retired into the interior; and were incessantly bowing and tossing about their arms 
in the most energetic manner. : 
As soon as I had a little recovered from my surprise at this strange display, I began to 
examine the performers more in detail. A slender creeping thread, irregularly crossing 
and anastomosing, so as to form a loose network of about three meshes in width, sur- 
rounded the margin of the Sabella's tube, adhering firmly to its exterior surface, in the 
chitinous substance of which it seemed imbedded (see Pl. XX. fig. a). Here and there 
free buds were given off, especially from the lower edge; while from the upper threads 
sprang the strange forms that attracted my notice. "These were fusiform bodies, about 
45th of an inch in height, whose lower extremities were of no greater thickness than the 
thread from which they sprang, with a head-like lobe at the summit, separated from the 
body by a constriction, immediately below which two lengthened arms projected in a 
direction towards the axis of the tube. : i 
Such was the external form of these animals; and their movements were still more 
extraordinary. The head-lobe moved to and fro freely on the neck; the body swayed from 
side to side, but still more vigorously backward and forward, frequently bending into an 
arch in either direction; while the long arms were widely expanded, tossed wildly upward, 
and then uro downward, as if to mimic the actions of the most tumultuous human 
påssion. pes i 
Whenever the Sabella protruded from its tube, these guardian forms were pushed out, 
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