PENNATULA. 195 
in proportion to the size of the stem, which is about the 
third of an inch in diameter. The breadth of the lobed or 
feather part is about an inch and a half. There are several 
polypes on each lobe,—in all, about thirty. It is rare in 
England and in Ireland, but in the north of Scotland it is 
frequently found on the fishermen’s lines when baited with 
mussels. In the Frith of Forth it is common. Sir J. G. 
Dalyell, who describes and figures it admirably, had sixty- 
four live specimens at once in his possession. He states 
that, “like other asteroid zoophytes, it is strictly a noc- 
turnal animal. It enlarges remarkably as evening comes 
on. It is then that the lobes are swollen, and the hydre 
most amply displayed in vigour, while the whole variable 
organic structure expands by intumescence.” 
Whether it can swim about, or remains fixed in the mud 
or sand, is a disputed point. There is high authority in 
proof of its natatory powers. Bohadsch says that it swims 
freely, and that he has seen it do so, using its pinne for 
this purpose as fishes do their fins. Ellis says “it is an 
animal that swims freely about in the sea,” and that this is 
effected by means of feather-like fins. Cuvier tells us that 
it has the power of moving by the contractions of the globe 
part, and the combined action of the polypes. Other na- 
