Campanularia. ZOOPHYTA. SERTULARIAD^. 549 



Sertularia dumosa, Flem. Edin. Phil. Journ. ii. 84 — Tubularia tubifera 

 (young), Johnston, Edin. Phil. Journ. xiii. 222. t. iii. f. 2, 3 — On Co- 

 rallines from deep water from Devon to Zetland. 

 Height nearly two inches, stem erect, slightly branched dichotomously, 

 and composed of several vertical tubes, becoming simple towards the extre- 

 mity ; cells arising from the stem, round, and projecting nearly at right an- 

 gles ; their base narrow, wrinkled, short, their length about twice the breadth 

 of the stem, with an even truncated extremity — This species has been known 

 to me since 1808, having then found it in the refuse of the oyster boats of 

 the Forth, and subsequently on other parts of the coast. Mr Montagu had 

 likewise observed it in Devon about tlae same time. It is not unlikely that 

 the yet obscure Sertularia imbricata of Adams (Linn. Trans, v. ii. t. ii. f. 5.), 

 may be identified with this species ; though the cells be exhibited as ovate 

 or subclavate, and the stem simple. 



194. C. gelatinosa. — Subordinate branches dichotomously 

 branched, cells on twisted footstalks, campanulate, with even 

 margins. 



Corallina filiformis (young), Ellis, Cor. 22. t. xii. f. c. C. and t. xxxviii. 



f. 3 — Sertularia gel. PaU. £1. 116. Flem. Edin. Phil. Journ. ii. 84. 



and PhiL Zool. ii. G16. t. v. f. 3 On stones near low-water mark, 



common. 

 The base of this sertularia, by which it adheres to st<jnes, is spreading 

 and spongy, and consists of numerous closely interwoven tubular fibres, 

 which rapidly approach to form the stem. The stem rises to nearly a foot 

 in height, and is so flexible as to move with every agitation of the water ; 

 it is thickest at the base, where it consists of numerous tubes ; but as these 

 diminish in number, until, at the top, there can only be perceived a single 

 branched thread, it tapers gradually to a pomt : it is nearly straight through- 

 out, and is seldom divided. The branches are disposed round the stem in 

 nearly an alternate order, and as they are longest towards the base, and gra- 

 dually diminish in length towards the summit, a graceful tapering outline is 

 produced ; they occur in pairs which have their origin nearly at the same 

 point ; they are not formed from the external tubes, as in some of the other 

 Sertularise, with compound stems, but from the central ones, those at the 

 surface turning aside to admit their exit ; these branches proceed from the 

 stem in nearly a perpendicular direction, and diverge from each other at an 

 angle of about 45° ; each branch is acutely conical, giving out, towards the 

 base, subordinate branches, likewise in pairs, similar to those on the main 

 stem ; at last these become alternate, and, gradually shortening, the subor- 

 dinate stem supports only alternate cells, and either terminates in twin cells, 

 in a single one, or in a clavate mass, containing the rudiments of a future 

 cell and polype. The cells are terminal, and are supported on short foot- 

 stalks which issue from the stem in alternate order ; they are bell-shaped, 

 somewhat produced, with an entire margin. The vesicles are ovate, ap- 

 proaching to cylindrical, with a contracted truncated mouth, covered with a 

 hemispherical lid ; they are solitary, nearly sessile, and arise in the divisions 

 of the branches or of the foot-stalks of the cells ; at the point of separation of 

 the larger branches there is usually a small twig, supporting 2 or 3 cells 

 with vesicles. The stems are of a brownish colour, opake, and of a firm 

 tough consistence, but in approaching the extremities they become soft, co- 

 lourless and transparent, so that the central stem of the pol3'pe can be easily 

 distinguished ; immediately above every division, whether formed by a 

 branch or foot-stalk, tliere are several transverse wrinkles, varying in num- 

 ber, being seldom fewer than 3, or more than 6 ; similar wrinkles occur on 

 the foot-stalks at the base of the cells. The stems at the divisions of the 

 branches are a little thickened, while the foot-stalks at the base of the cells 



