96 
Sertularia imbricata, Turton’s Lin., vol. 4, p. 683. Ste^' 
art’s Eleni., vol. 2, p. 450. Serialaria imbricata, Sertula r J_ a 
verticillata, Templeton in Mag. Nat. Hist., vol. 9, p. 4*3 •> 
fig. 66. 
Hab. On fuci near low water mark. Polperro. 
common. 
This is a small confervoid species of a light brown or h° r “ 
colour, and is parasitical on different species of fuci near 
shores. Its stem is formed of a semi-transparent zig- z3 ® 
line, and gives off its branches very irregularly, but in so®^ 
what an alternate manner. It is generally creeping a ° 
frequently covers a surface of several inches in extent, fr° 
which a few tufts arise erect. The cells arise irregularly^ 
various parts of the polypidom, in dense clusters or in siPr ^ 
rows; they are ovate with contracted terminal apertures a8 j 
are deciduous. The stein and branches are frequently mark 
with round or oval apertures, which are the marks ot c c g 
which have fallen off'. The polypes are very active and h 8 ’ 
eight ciliated tentacula, they appear to be very timid ; 18 
protrude themselves, so far as the tentacula very slowly, 
afterwards quickly; but the least motion, or shade will ® a 
them contract in a very sudden and unexpected man°®j 
The cells to be seen in a perfect state must be exam® 
while the specimen is recent, for when it is dried, 111 , 
frequently fall oft’ and always look different from nat® ’ 
this observation applies not only to this, but to all 
horny fistular species, so that descriptions taken from d r) 
specimens will not frequently apply to the living. 
DODDER CORALLINE. F. Cuscuta. Creeping, ^ ' 
der, horny, branched ; branches opposite, nearly P er P, t t>( j. 
dioular to the stem ; cells ovoid, numerous, crow® 
PI. xvii., fig. 3. . 
Climbing Dodder-like Coralline, Ellis’ Coral., p. 28, p*' . ;j 
fig. c C. Sertularia cuscuta, Ellis and Solauder’s Zo^r ^ 
p. 53. Turton’s Lin., vol. 4, p. 680. Stewart's Eleni., 
p. 444. Valkeria cuscuta, Johnston’s Brit. Zooph., p- “ 0 ' > 
Hab. Parasitic, on fuci and corallines. Not unco® 83 
Polperro. Goran. . e 
This species when nearly deprived of its cells, has ef . 
appearances of Valkeria cuscuta as figured by Ellis ; 0 jj, 
wise it bears but little resemblance to it. It is conte r ' ^ 
horny, creeping and very slender. It sometimes atta®* gti g 
height of lour inches, but is most commonly found ab<® ^j| 
or two. It arises from creeping tubular fibres wbich 
along on fuci and other marine productions. The b „ r “osif 
arc numerous, and frequently branch again; they are 
and stand nearly at right angles to the stern. The 
