104 COHALLINACE/E. 



Corallines, are filiform, either pinnated, or dichotomous, the 

 branches formed of strings of calcareous articulations, trun- 

 cated at the upper extremity and rounded at the lower, each 

 articulation connected with that above and below it by a 

 flexible joint, composed of cellular tissue, destitute of car- 

 bonate of lime. This joint in our British species is scarcely 

 obvious till after maceration, but in many exotic species (of 

 Amphiroa] it is so long as to interrupt the continuity of the 

 articulations, and is either naked, or coaled with wart-like, 

 calcareous tubercles. The form of the articulations varies 

 extremely, and often in the same species, or even in the same 

 specimen, so that the determination of these plants is some- 

 times difficult. In many the articulations are cylindrical ; in 

 others oval and compressed ; in some flat and irregularly shap- 

 ed ; but in the greater number they are heart-shaped or wedge- 

 shaped, with the upper angles frequently prolonged with horns. 



The fructification consists of hollow, external or immersed 

 conceptacles, containing a tuft of oblong spores, divided at 

 maturity, by three horizontal fissures, into four parts. They 

 are therefore tetraspores ; precisely similar to those of Ploca- 

 mium, Hypnea, &c. The nature of the conceptacle varies, 

 even in the same species. Thus, in Corallina, it is normally 

 formed by the metamorphosis of the terminal articulation of 

 the branches, which swells at the sides and becomes pierced 

 at the apex. But in C. squamata, and even in C. officinalis, 

 other articulations frequently bear numerous small, hemi- 

 spherical conceptacles on their sides; and sometimes the 

 whole surface is warted with such ; and these irregular organs 

 are equally furnished with tetraspores as the normal ones. 

 These latter conceptacles, which are irregular in Corallina, 

 are the normal fruit of Amphiroa, a genus chiefly from the 

 Southern Ocean. In Jania the conceptacle is similar to that 

 of Corallina, except that it generally bears a pair of ramuli 

 (resembling the antennae of an insect) from its upper angles. 



The Corallines are found in all parts of the Ocean, but are 

 much more numerous in warm than in cold countries, and 

 some of the species of the tropical and sub-tropical ocean are 

 among the most beautiful of marine vegetables. Until re- 

 cently the plants of this order were, with other calcareous 

 Algae, confounded with the zoophytes, or polypiferous corals. 

 They are, however, undoubtedly, of vegetable nature ; and 

 when the lime which they contain is removed by acid, the 

 vegetable framework, concealed beneath it, is found to be of 

 a similar structure to that of other Rhodosperms, to which 



