CAMPANULARIAD^E : LAOMEDEA. 103 



circular, more or less elevated aperture : they are commonly pro- 

 duced in spring. 



The polypes are reddish ; and the cells, within which they nestle, 

 so hyaline and tender, that specimens gathered amongst the rejecta- 

 menta of the sea are mostly deprived of them. 



Pallas has most aptly described this species, and I quote a part 

 of his description to render our own more complete : " Substantia 

 stirpis junioris, extremorumque maxime ramulorum cum calyculis 

 albida, mollis, tenera ; adultioris, per truncum et principaliores 

 ramos, testacea, versus ramos sensim dilutior et tenerior ; tandem- 

 que antiquae et mortuae atra corneaque, superstitibus tantum ramis 

 principalioribus, (ut Ellis tab. 12, a. A.)" 



2. L. GENICDLATA, stem zig-zag, simple, rarely with one or 

 two branches ; cells on annular stalks from the joints, cam- 

 panulate, with an even rim ; vesicles axillary, ovate. Doody. 



PLATE XXV. FIG. 1, 2. 



Fucoides setaceum temiissime alatum, Raii Syn. i. 38, no. 6, pi. 2, fig. 2. Ellis in 

 PhiL Trans, abridg. x. 491, pi. 12, fig. 1, a. ^.Knotted- thread Coralline, Ellis 

 Corall. 22, no. 19, pi. 12, b. B. Sertularia geniculata, Lin. Syst. 1312. Pall. 

 Elench. 117. Mull. Zool. Dan. iii. 61, tab. 117, fig. 14. Ellis and Soland. 

 Zooph. 49. Lam. Anim. s. Vert. ii. 120 : 2de dit. ii. 149. D. Chiaie Anim. 

 s. Vert. Nap. iv. 143. Laomedea geniculata, Lamour. Cor. Flex. 208. Couch 

 Zooph. Cornw. 20 : Corn. Faun. 38, pi. 10, fig. 1. Campanularia geniculata, Flem. 

 Brit. Anim. 548. Johnston in Trans. Newc. Soc. ii. 255. Van Beneden Camp. 

 34, pi. 3, fig. 1 6. Monopyxis geniculata, Ehrenb. Corall. des roth. Meer. 73. 



Hab. Parasitical and gregarious on sea-weeds that grow near low- 

 tide mark, especially on the frond of Laminaria digitata ; very com- 

 mon. " Some of the finest specimens I have seen were growing 

 on the dorsal and caudal fins of a Picked Dogfish." R. Q. Couch. 

 " It is sometimes found on Zostera marina, but is common on 

 Algae, especially on Halidrys siliquosa and Laminaria digitata. The 

 incipient state appears very different on these two plants. The 

 roots (if so they may be termed) twine round the stem and vesicles 

 of the Halidrys in an ordinary manner, so as not to attract atten- 

 tion ; but on the broad leaves of the Laminaria they often form a 

 regular piece of network, having meshes of various size, with their 

 junction tied in a knot, as it were by fairy fingers. From each 

 knot, in due time, springs the zoophyte known as L. geniculata." 

 W. Thompson. 



Polypidom attached by a creeping tubluar thread, erect, about 



