96 
FiustreLta HispipaA and its DrvreLopMEeNnT. By Prver 
Reprern, M.D. Lond., Lecturer on Anatomy and Phy- 
siology, and on Histology, in the University and King’s 
College, Aberdeen. 
(Read before the Natural History Section of the British Association, at 
Dublin, in August, 1857.) 
Tue Flustrella hispida of Dr. Gray is the Flustra hispida 
of Fleming, and the Plustra carnosa of Dalyell and Johnston. 
It seems to have been overlooked by Mr. Gosse, in his ‘ Marine 
Zoology,’ and to have attracted much less attention than it 
deserves, when its beauty and general distribution are con- 
sidered. 
I have found it abundant on the rocky coast of Kincardine- 
shire, for eleven miles south from Aberdeen; on the Irish 
coast at Howth, Dalkey, and Bray, in the Bay of Dublin, 
and at Wicklow; also in North Wales, at Llandudno. It 
usually grows on the fronds of /ucus serratus, but in the im- 
mediate vicinity of Aberdeen, it is excessively rare on that 
Fucus, but abundant on Chondrus mamiilosus. It forms 
round or oblong, brown, hairy patches, about a line thick, 
which extend completely round narrow fronds, but are con- 
fined to one side of broad ones. It is mvariably encrusting. 
The extent of the coeneecium rarely exceeds an inch on the 
Kincardineshire specimens, but it extends for three or four 
inches on those gathered in Dublin Bay and North Wales. It 
occurs on the Fucus, together with the Alcyonidium hexa- 
gonum (Hinks) and the Cyclowm papillosum (Hassall) ; on the 
specimens of Chondrus the Flustrella occurs with Alcyonidium 
hirsutum. 
The ccoencecium is thick in the centre ; thin, and composed 
of the last-formed individuals at the edges. The cells radiate 
from the centre, and they are imbricated in various degrees 
in different parts, the whole length of the cell, or merely its 
summit, being visible on the surface. The arrangement of 
the cells is variable, but generally alternating. When 
allowed to dry on the plant, the ccencecium presents the 
appearance of a wrinkled, hairy membrane; when it is sliced 
from the plant, and dissected with needles, a large quantity 
of viscid matter escapes from its cells. 
The wall of each cell is set with rigid, reddish-brown, 
pointed and slightly curved hairs, very numerous, and, for 
the most part, occupying the whole circumference in the 
Kincardineshire specimens, but very few in number, and set 
