Sertularia. Z. HYDROIDA. 135 



numerous seg-ments. In Plate XI. Fig. 3, I have given a fig-ure of 

 such a specimen selected from many others on account of its greater 

 diverg-ence from the usual character of the species. When, on the 

 contrary, the polypidom attains a foot or more in height, the lower 

 half of the stem loses its branches and cells, and becomes entirely 

 naked. I think it likely that such a specimen, of the unusual size of 

 3 feet, constitutes the Sertulm'ia uber of Sir J. G. Dalyell in Edin. 

 New Phil. Journ. xvii. 412. 



16. S. CUPRESSINA, polypidom cauliferous ; cells nearly op- 

 posite, tubulous, adnate, the aperture scarcely contracted, bilabiate, 

 uiith two minute spinous teeth ; vesicles nearly oval. — Ellis. 



Plate XIII. 



Sea- Cypress, ^ffis, Corall. 7, No 3, pi. 3, fig. a, A. Sertularia cupres- 



sina, Lin. Syst. 1308. Ellis and Soland. Zooph. 38. Berk. Syn. i. 

 216. Turt. Ginel. iv. 677. Wern. Mem. i. 564. Turt. Brit. Faun. 

 213. Stew. Elem. ii. 442 Bosc, Vers, iii. 108. Lam. Anim. s. Vert, 

 ii. 118. Lamour. Cor. Flex. 192. Corall. 84. Hogg's Stock. 32. Tem- 

 pleton in loc. cit. 468. Stark, Elem. ii. 440, pi. 8, fig. 12. Risso, 



L'Europ. merid. v. 311 La S. cypres, Blainv. Actinol. 480 Dy- 



namena cupressina, Flem. Brit. Anim. 543. 



Hab " The Sea-cypress is chiefly found in deep water on the coast 

 of Yorkshire, Scotland, and the north of Ireland," Ellis. Scarbo- 

 rough, Mr Bean. Frith of Forth, Jameson. Cork Bay, Mr J. V. 

 Thompson. On the shore of iNIagilligan Strand, County Derry, 

 TempJeton. 



This is in general a larger and stouter species than the preceding, 

 with longer branches more decidedly fan-shaped, the pinnae being 

 closer and more parallel to one another. The cells are in two rows, 

 nearly opposite, smooth and pellucid, adnate, with the margin of the 

 comparatively wide aperture sinuated so as to form two or some- 

 times three prominent denticles. The branches in some specimens 

 are gTacefully arched, bending as it were under the load of pregnant 

 ovaries which they carry, and which are arranged in close-set rows 

 along the upper side of the pinnae. They are of an oval shape, 

 smooth, attenuated at the base, with sometimes a sharp spine at each 

 corner of the apex, but these are oftener absent. 



This and the preceding have a distinct stem, in which they differ 

 from all the other native species, which are pre-eminently frondose 

 or homologous, the offsets and pinnae being in all respects the same 

 as the primary shoot. Pallas maintains that they constitute but one 



species, his S. cupressina, Elench. 141 the charactei's assigned to 



them respectively being far from specilical, since he found, on one 



