C 422 ] 
very much in their exterior form and dze, and con- 
fequentlyare of very different fpecies. 
The Idem of the fuckers of this animal is of a 
cylindrical form ; from the upper part proceed 8 
fine white filaments or claws to catch their food : 
when they retreat on the alarm of danger they 
draw themfelves into their cafes, which are formed 
like the denticles of the Corallines ; but here each 
denticle is furnifhed with fpiculas, which clofe toge- 
ther round the entrance of the denticle, and protect 
this tender part from external injuries. 
Some time after I had made my remarks on this 
very extraordinary animal, the Royal Society did 
me the honour to recommend to me, for my opinion, 
fome very curious obfervations lately publifhed 
by Dr. Bohadfch of Prague, a book of great 
merit, which fhews that the author has taken a good 
deal of pains, in examining very minutely into thoTe 
animals called by the old authors Zoophytes: but as 
many of them have not the lead refemblance to vege- 
tables, I fhall beg leave to pafs over fuch, and only 
confine myfelf to this clals of the Penna marina, 
which he feems to have been happy in obferving; and 
therefore fhall take the liberty to add fuch of his ob- 
fervations, as the opportunity of his feeing this 
animal alive in fea-water afforded him, without 
which it would have been impoflible for me to 
have had the oleafure of gratifying you, and 
the reft of the Royal Society, fo fully on the 
fubjedt. 
Some of the mod curious remarks of Dodtor Bo- 
hadfch on the anatomy of this animal, as alfo on 
the appearance of it while alive in lea-water, are 
as follows. 
4 
« When 
