CmSIADiE : 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 ; tlie upper por- 

 tion free and divergent. Fig. 63. 



1. 0. coRNUTA, cells tuhulous, curved^ the apertures all turned 

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



Plate L. Fig. 1, 2. 



Goat's-hom Coralline, Ellis Corall. 42, no. 10, pi. 21, fig. c, C. — Couch Zooph. 

 Comw. 39. — Sertiilaria cornuta, Lin. Sj'st. 1316 (edit. x. 810). Berh. Syn. i. 

 220. Esper Pflanz. Sert. tab. 19, fig. 1-3.— Celliilaria falcata, Pall. Elench. 76. 

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

 Lam. Anim. s. Vert. ii. 1 39 : 2de edit. ii. 1 87. — Eucratea cornuta, Lamour. Cor. 

 Flex. 149. i?«sso L'Europ. Merid. V. 319. Ffem. Brit. Anim. 541. Templeton 

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

 comee, M. Edivards in Ann. des Sc. Nat. n. s. ix. 240, pi. 8, fig. 2. — Crisia cor- 

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

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



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

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

 very generally distributed on our coasts j 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. 



