60 SYNOPSIS OF BRITISH SEAWEEDS. 



brachiatus being lodged in swellings or enlargements of 



the smaller branches in the axils oi the opposite ramuli, 



and in this being formed by a metamorphosis of the ramuli 

 themselves. It appears by no means indifferent to what 

 plant it attaches its fronds, being very generally found 

 growing on Ptilota sericea, though frequently also on Cla- 

 dophora rupestris. Dr. Hooker brought from Cape Horn 

 an Ectocarpus (E. geminatus) closely resembling this. 



13-4. brachiatus {The cross-branched JEctocarpus) ; frond finely 

 tufted, feathery, much branched ; the branches free, opposite 

 orquaternate; ramuli opposite, spreading; capsules imbedded 

 in the branches, forming oblong swellings situated on the 

 lesser branches, or in the axils of two opposite ramuli, Harv. 

 in Hook. Br. El. v. 2. p. 326. (Atlas, PL XX. Fig. 90.) 

 Ectocarpus cruciatus, Ag. Conferva brachiata, Eng. Bot. 

 Hab. England, and east and south of Ireland. Rare. In ditches 

 of brackish water, among Enteromorpha compressa; in the sea, 

 growing on Rhodymenia palmata. 

 In the year 1801, Mr. Dawson Turner, and in 1808, Si? 

 W. J. Hooker, found in ditches of brackish water, by th« 

 seaside on the Norfolk coast, a plant of which a figure and 

 description appeared in the 'English Botany' under the 

 name of Conferva brachiata. That figure evidently repre- 

 sents a species oi Ectocarpus, having opposite branches 

 and immersed fruit. The Norfolk plant has not been found 

 of late years, and no specimen now exists in Sir W. J. 

 Hooker's Herbarium. The English Botany plate conse- 

 quently remained for many years the only record of the 

 species, until Mrs. Griffiths discovered in Torbay the plant 

 of which a figure is now given, possessing apparently the 

 leading or essential characters of the Norfolk one, but 

 growing in the open sea, and always as a parasite on Rho- 

 dymenia palmata. 



95. Mertensii (Mertens's Ectocarpus); distichous; branches op- 

 posite, of unequal length, linear, mostly undivided, closely 

 set, throughout their w T hole extent, with slender, subulate, 

 opposite ramuli ; joints of the stem longitudinally striate, 

 transparent, with a central coloured band, rather shorter 

 than their breadth ; spores binate, imbedded in the ramuli, 

 Ag. Sp. Alg. v. 2. p. 47. (Atlas, PL XXII. Fig. 96.) 



Conferva Mertensii, E. Bot. 



Sab. On mud-covered rocks and stones, near low-water mark, 

 and at a greater depth. Annual. April and May. Kare ; 

 but pretty generally distributed. 



