42 PHILOSOPHICAL TRANSACTIONS. [aNNO 17^3. 



To come now to consider more minutely those pinnulae, or feather-like fins, 

 that project on each side and form the upper part of this animal. These are 

 evidently designed by nature to move the animal backward or forward in the sea 

 consequently to do the office of fins, while at the same time, by the appearance 

 of the suckers or mouths furnished with filaments or claws, they were certainly 

 intended to provide food for its support; for notwithstanding what Linnaeus has 

 said in regard to its mouth, in his system of nature, viz. Os baseos commune 

 rotundum, Mr. E. could not, with the help of the best glasses, discover that the 

 point of the base was penetrated in the least, so that he is clearly of opinion, 

 that this animal, like the hydra arctica or Greenland polype, described in his 

 Essay on Corallines, nourishes and supports itself by these suckers or polype-like 

 filaments; that by these both kinds take in their food, and have no other visible 

 means of discharging the exuviae of the animals they feed on, than by the same 

 way which they take them in; and that, from attentively considering the struc- 

 ture and manner of living of both these animals, he classes them in the same 

 genus of pennatula, though they vary very much in their exterior form and size, 

 and consequently are of very different species. The stem of the suckers of this 

 animal is of a cylindrical form; from the upper part proceed 8 fine white fila- 

 ments or claws, to catch their food: when they retreat on the alarm of danger, 

 they draw themselves into their cases, which are formed like the denticles of the 

 corallines, but here each denticle is furnished with spiculae, which close together 

 round the entrance of the denticle, and protect this tender part from external 

 injuries. 



Some of the most curious remarks of Dr. Bohadsch on the anatomy of this 

 animal, as also on the appearance of it while alive in sea water, are as follow: 

 " When the trunk is opened lengthwise, a saltish liquor flows out of it, so viscid 

 as to hang down an inch ; the whole trunk of the stem is hollow ; its outward 

 coriaceous membrane is more than a line thick, and forms a strong covering to 

 it: between this and another thinner membrane of the pinnated part of the 

 trunk, are innumerable little yellowish eggs, floating in a whitish liquor, about 

 the size of a white poppy seed; these are best seen when the trunk is cut across; 

 this thin membrane lines the whole inside of the trunk, in which we observe 

 nothing but a kind of yellowish bone, which takes up 3 parts of the cavity. 

 This bone, in some of these animals, is above 2\ inches long, and about half a 

 line thick; in the middle part of it, it is quadrangular; towards each end it grows 

 round and very taper : that end is smallest which is nearest the top of the pin- 

 nated trunk. The whole bone is covered with a yellowish clear skin, which at 

 each end changes into a ligament; one of which is inserted in the top of the 

 pinnated trunk, the other in the top of the naked trunk ; by the help of this 

 upper ligament, the end of this little bone is either contracted into a very narrow 



