112 SYNOPSIS OF BRITISH SEAWEEDS. 



which are natives of the warmer parts of the temperate 

 zone, about lat. 34 to 10°. G.filicina Lb the onlj 

 which lias a very wide distribution, and it extends from 



tlie tropica] ocean i«» the southern shores of Britain, where 

 it becomes very mm-h dwarfed in >\z<>. bui where, never- 

 theless, it frequently produces fruit of both kinds. In the 

 Mediterranean Sea, where it is common, the fronds aie BIZ 

 or eighl inches in expansion, and regularly and closely 

 bipinnate, the pinnules an inch or more in length. The 

 only British plant with which this is likely to be con- 

 founded, is Gelidium cornewn, t<> some varieties of which 

 it bears a very strong external resemblance. Its softer 

 and more membranous substance will generally distinguish 

 it to the feel ; and the microscope will point out a differ- 

 ence of structure, when closely examined. If in a state of 

 fruit, there can be no difficulty in discriminating between 

 them. 



LX. GELIDIUM. 



191. corneum (The horny Gelidium) ; frond between cartilagi- 

 nous and horny, flattish, distichous ; branches linear, attenu- 

 ated at each end, pinnate or bipinnate ; pinnules opposite 

 or alternate, patent, obtuse, Lamour. JEss. p. 41. (Atlas, 

 PI. XLIV. Fig. 199.) 



Sphaerococcus corneus, Ag. Fucus corneus, Huds. F. pinnatus, 



Huds. F. Hypnoides, Desv. F. pusillus, Stack. F. cses- 



pitosus, Stack. F. crinalis, Turn. 

 Hah. On submarine rocks, from the verge of high water to the 



extreme of low water, and extending to a greater depth ; 



often fringing the margin of tide-pools in places shaded by 



other Algse. Common on all our shores. 

 A most variable plant, found in some of its varieties in 

 almost all seas, and abundant everywhere. 



192, cartilagineum [The cartilaginous Gelidium) ; frond several 

 times pinnated, pinna? and pinnula? alternate, erecto-patent, 

 with rounded axils, linear, obtuse ; tubercles elliptical, mu- 

 cronate, immersed in the ultimate pinnules, Gaill. lie. sum. 

 p. 15. (Atlas, PI. XLII. Fig. 192.) 



Gelidium concatenatum, Lamour. Gr. versicolor, Lamour. Spha> 

 rococeus cartilaginous, Ag. Fucus cartilflgineufl, Linn. F. 

 capensis, Gm. F. versicolor, Gm. 



Ilab. Thrown ashore, occasionally, on the south coast3 of Eng- 

 land. Perennial. 

 The specimen, from which the figure given with this 



