96 



Sertularia imbricata, Turton's Lin., vol. 4, p. 683. Stew- 

 art's Eleru., vol. 2, p. 450. Serialaria imbricata, Sertularia 

 verticitlata, Templeton in Mag. Nat. Hist., vol. 9, p. 467, 

 fig. 66. 



Hub. On fuci near low water mark. Polperro. Not 



common. 



This is a small confervoid species of a light brown or horn 

 colour, and is parasitical on different species of fuci near the 

 shores. Its stem is formed of a semi-transparent zig-zag 

 line, and gives off its branches very irregularly, but in some- 

 what an alternate manner. It is generally creeping and 

 frequently covers a surface of several inches in extent, from 

 which a few tufts arise erect. The cells arise irregularly on 

 various parts of the polypidom, in dense clusters or in single 

 rows; they are ovate with contracted terminal apertures and 

 are deciduous. The stem and branches are frequently marked 

 with round or oval apertures, which are the marks of cells 

 which have fallen off. The polypes are very active and have 

 eight ciliated tentacula, they appear to be very timid ; they 

 protrude themselves, so far as the tentacula very slowly, but 

 afterwards quickly; but the least motion, or shade will make 

 them contract in a very sudden and unexpected manner. 

 The cells to be seen in a perfect state must be examined 

 while the specimen is recent, for when it is dried, they 

 frequently fall off and always look different from nature ; 

 this observation applies not only to this, but to all these 

 horny fistular species, so that descriptions taken from dried 

 specimens will not frequently apply to the living. 



DODDER CORALLINE. V. Cuscuta. Creeping, slen- 

 der, horny, branched ; branches opposite, nearly perpen- 

 dicular to the stem ; cells ovoid, numerous, crowded. 

 Pi, xvii., fig. 3. 



Climbing Dodder-like Coralline, Ellis' Coral., p. 28, pi. 14, 

 fig. c C. Sertularia cuscuta, Ellis and Solander's Zooph., 

 p. 53. Turton's Lin-, vol. 4, p. 680. Stewart's Elem., vol. 2, 

 p. 444. Valkeria cuscuta, Johnston's Brit. Zooph., p. 252. 



Hab. Parasitic, on fuci and corallines. Not uncommon. 

 Polperro. Goran. 



This species when nearly deprived of its cells, has all the 

 appearances of Valkeria cuscuta as figured by Ellis ; other- 

 wise it bears but little resemblance to it. It is confervoid, 

 horny, creeping and very slender. It sometimes attains the 

 height of four inches, but is most commonly found about one 

 or two. It arises from creeping tubular fibres which trail 

 along on fuci and other marine productions. The branches 

 are numerous, and frequently branch again ; they are opposite 

 and stand nearly at right angles to the stem. The whole 



