Alcyonidium. 
Z. ASCIDIOIDA. 
303 
be distinct from ours, for a very careful examination has satisfied me 
that the tentacula are 16 in number. 
D’Orbigny says that the Ulva diaphana of the Flore Fra^aise 
“ n’est autre chose qu’un amas de series d’oeufs d’une espece de gas- 
t^ropode nu." Mem. du Museum, vi. 181. The description, how- 
ever, so evidently belongs to the Alcyonidium before us, as to make 
it almost certain that this remark has originated in some misapplica- 
tion of it. 
2. A. hirsutum, polypidom variously divided , compressedy 
the surface covered with minute conical papillae or polype~cells. 
Fleming. 
Plate xlii. Fig. 1, 2. 
Alcyonium gelatinosum, Fabric. Faun. Groenl. 447 A. hirsutum* 
Flem. Brit. Anim. 517. Johnston in Zool. Journ. iv. 418. and in Trans. 
Newc. Soc. ii. 251, pi. 9, fig. 1. L’A. velu, Blainv. Actinolog. 525. 
Hab. Parasitical on various sea-weeds, at low-water mark, very 
common on the coasts of Scotland and North of England. Coast of 
Devonshire, Mr Jos. Alder. 
Polypidom variously divided, often proliferous, sometimes sub-cy- 
lindrical, commonly flattened and palmate, of a dirty straw-yellow 
colour, often partially stained with red, and marked with numerous 
yellowish circular spots irregularly disposed. It is thickish, some- 
what cartilaginous, and to the naked eye resembles a compact sponge. 
When viewed through a common magnifier, the surface is seen to be 
covered with close-set conical transparent papillae, each of which is a 
cell containing a polype with 16 long filiform tentacula, and in its 
structure resembling the polype of a Flustra. The yellowish spots, 
mentioned in the description, are produced by clusters of ova lying 
imbedded in the cellular texture. These are opaque milk-white, 
large enough to be easily visible to the eye, of a roundish figure, 
but not all of them alike, for some are ovate, and others incline 
to a heart-shape, rather compressed, the surface uneven. The egg is 
not clothed all over with cilia, but there is a fringe of cilia encircling 
it ; these cilia appear to be of a yellowish colour, and to be hooked 
near the apices, (wood-cut No. 7, page 51.) They are of equal size 
and shape, and all inclined in one direction, moving with a uniformity 
and quickness which is admirable and very pleasing to the beholder. 
When the egg is at rest, their velocity is not diminished, excepting 
at the will, so to speak, of the ovum, for it may be seen to become 
slower and less constant, to cease entirely for a moment, and again 
be renewed with its former force. The egg at rest will at once start 
