SfiRTULARiA. Z. HYDllOIDA. 121 



articulated, cylindrical or somewhat dilated at the aperture. Vesicles 

 mimerous, scattered or imperfectly clustered, large and shaped some- 

 what like the flower of a Calceolaria, with a short tubulous aperture 

 in the middle of its concavity, which is on the superior and inner as- 

 pect. 



I have named this curious and very interesting species after its 

 discoverer, to whose kindness I am indebted for the specimen that fur- 

 nished our figure and description. In habit and structure it closely 

 resembles Th. halecina, from which it is, however, at once distin- 

 guished by its remarkable ovaries. 



3. T. MURiCATA, vesicles roundish or ovate, echinated. Dr 

 David Skene. 



Plate VII. Fig. 3, 4. 

 Sertularia muricata, Ellis and Soland. Zoopb. 59, pi. 7, fig. 3, 4. Turt. 

 Gmel. iv. 681. Turt. Brit. Faun. 215. Stew. Elem. ii. 445. Jame- 

 son in Wem- Mem. i. 564. Flem. Brit. Anim. 543. Hogg's Stockton, 



34. JBosc, Vers, iii. 115 Laomedea muricata, Lamoiir. Cor. Flex- 



209. Corallina, 92 La Sertulaire muriquee, Blainv. Aotinol. 480. 



La Campaniilaire muriquee, Ibid. 473. 

 Hah. On old shells in deep water. The sea at Aberdeen, Skene. 

 Frith of Forth, Jameson. Seaton, J. Hogg. Near Scarboi'ough, 

 TV. Bean. 



Polypidom from 2 to 4 inches high, rooted by a fibrous entangled 

 mass, irregularly bi'anched, stout and rigid, yellowish-brown ; the 

 stem and branches composed of capillary tortuous tubes closely ag- 

 glutinated, but the extremities of some of them become free and ap- 

 pear hke simple fibres ; branches erecto-patent, slightly tapered at 

 the point. Cells visible only on the simple fibres, small, alternate, 

 separated by an oblique joint, sessile, campanulate, with an entire 

 even aperture. Vesicles very numerous and often crowded, shortly 

 stalked, roundish or ovate, somewhat compressed, and rough with 

 prickles arranged in lines on elevated striae : when filled with ova the 

 centre is of a deep chesnut-brown colour. 



May not the obscure Sertularia echinata of Linnaeus be re- 

 ferable to this species ? 



6. Sertularia,* Linnaeus. 

 Character. Polypidoms rooted, plant like, variously branch- 

 ed, the divisions or branches formed of a sinr/le tube divided at 

 regular intervals by imperfect septa : cells paired or arranged in 



* From sertula, the diniiruitive of serta, a garland. 



