42 SYNorsis of British seaweeds. 



tiful, owing to the greai Length and full greenish-olive hue 

 of the filaments composing the periphery, which are - 

 a Looser gelatine than in any other of our British kinds, 

 and give the frond a Bingularly villous appearance to the 



naked eye. In this respect it differs from M. Griffith- 

 siana, which is of a much firmer and more compact sub- 

 stance. 



XXVIII. LEATHESIA. 



56. tuberiformis {The inLrr-shaped Leathesia) ; fronds oliva- 



ceous, tuberous, when young stuffed with cottony fibn 

 length hollow, ,S'. F. Gray, Nat Ar. Br. PL v. 1. p. 301. 

 (Atlas, PL XIII. Fig. 51.) 

 Leathesia marina, Eudl. L. difFormis, Aresch. Corynephora 

 marina, Ag. Chsetophora marina, Lyngb. Xostoc man- 

 num, Ag. Tremella difformis, Linn. Rivularia tuberifor- 

 mis, IE. Bot. 

 Hah. Atlantic shores of Britain. Between tide-marks, on rocks, 

 corallines, and the smaller Algae ; very common. Annual. 

 Summer and autumn. 

 Common on all our rocky shores, first appearing about 

 April or May in the form of little pea-like buttons, at- 

 tached to small Algae, or grouped in clusters on the surface 

 of rocks and corallines, and, as the season advances, gra- 

 dually acquiring size ; the fronds becoming hollow and 

 cohering in masses. I adopt the name selected by the 

 founder of the genus, and which dates from 1809, because 

 it well expresses the aspect of the plant, — "like a cluster 

 of small potatoes." 



57. Berkeley! {Berkeley 's Leathesia) ; fronds dark brown, de- 



pressed, fleshy, solid; filaments denselv packed. (Atlas, 



PI. XV. Fig. 59.) 

 Chsetophora Berkeleyi, Grev. 

 Hob. South of England and west of Ireland. On submarine 



rocks, between tide-marks ; exposed at low water. Annual. 



Summer. 

 A small plant, more curious than beautiful, first noticed 

 by the Kev. M. J. Berkeley on rocks at Torquay. On the 

 ■west coast of Ireland it is plentiful in several places, and 

 probably is pretty generally distributed along our shores, 

 being overlooked on account of its being often nearly of 

 the colour of the rock on which it grows, and resembling, 

 in its fleshy appearance and feel, the collapsed body of the 



