CRISIADJ: : CRISIDIA. 287 



cells. The characters, however, which distinguish C. geniculata 

 from C. eburnea appear to be rather those of a variety than of 

 a species ; and I have specimens in which the characters of both 

 species seem to co-exist. 



The polypes have eight tentacula, which, according to Milne- 

 Edwards, is the number throughout this family. 



7. CRISIDIA,* M. Edwards. 



CHARACTER. Cells linked in a single series ; the upper por- 

 tion free and divergent. Fig. 63. 



1 . C. CORNUTA, cells tubulous, curved, the apertures all turned 

 in one direction, with a long bristle above each cell. Ellis. 



PLATE L. FIG. 1, 2. 



GoatVhorn Coralline, Ellis Corall. 42, no. 10, pi. 21, fig. c, C. Couch Zooph. 

 Cornw. 39. Sertnlaria cornuta, Lin. Syst 1316 (edit. x. 810). Berk. Syn. i. 

 220. Esper Pflanz. Sert. tab. 19, fig. 1-3. Cellularia falcate, Pall. Blench. 76. 

 C. cornuta, Hogg's Stock, 35. Cellaria cornuta, Ellis and Sdand. Zooph. 25. 

 Lam. Anim. s. Vert. ii. 139 : 2de edit. ii. 187. Eucratea cornuta, Lamour. Cor. 

 Flex. 149. Risso L'Europ. Merid. v. 319. Flem. Brit. Anim. 541. Templeton 

 in Mag. Nat. Hist. ix. 469. Unicellaria cornuta, Blainv. Actinol. 462. Crisidie 

 cornee, At. Edivards in Ann. des Sc. Nat. n. s. ix. 240, pi. 8, fig. 2. Crisia cor- 

 nuta, Johns. Brit. Zooph. 260. Hassatt in Ann. and Mag. Nat. Hist. vi. 1 70. 

 Couch Corn. Faun. iii. 97, pL 17, fig. 4 ; and in the Zoologist, ii. 1095. 



Hob. Parasitical on other corallines, and "adhering to Fuci 

 beyond low water-mark, not common," Fleming. It is, however, 

 very generally distributed on our coasts ; and in many parts occurs 

 plentifully. 



Polypidom sometimes half an inch in height, very slender, erect, 

 confervoid, white and brittle when dry, rooted by a few tubular 

 fibres, alternately branched, the secondary branches unilateral or se- 

 cund. The coralline consists of a series of cells placed one above 

 another, the upper cell originating from the one below near the 

 middle, at its point of divarication from the straight line ; and 

 a long tubular spine, which overtops the cell, rises from the same 

 place. The cells are curved, tubular, the upper half everted, 

 with a plain circular patulous aperture. In some specimens oval- 

 shaped vesicles are found scattered over the polypidom : they ori- 

 ginate from the base of a cell, are specked, and have a small tube at 



* Formed from Crisia, and very faulty, because it cannot be used in the plural, 

 that being a family designation. 



