Desmares'ia.] ALGJE INARTICULATE. 273 



Shores of the island of Islay, one of the southern Hebrides, James 

 Chalmers. 0.— In length from 2 to 8 or 10 inches, obtuse, sometimes 

 almost obovate, of a thin and flaccid texture, with an extremely short 

 stipes. 



Tin be IV. Sporochxoide E. 



Plants all marine, of an olivaceous or yellowish -green colour, 

 not changing to black in drying ; of a curtilayineo-membranaceous 

 substance, becoming flaccid almost immediately after exposure to 

 the air, in some cases acquiring, under suck circumstances, a rerdi- 

 gris-green colour, and then possessing the property of rapidly de- 

 composing other delicate Algcc in contact with them. Frond with 

 a scutate (rarely tomentose) root, flat, compressed or cylindrical, 

 with distichous (rarely irregular) branches, and bearing in most 

 species, at some period of their growth, little pencil-like deciduous 

 tufts off ne green filaments. Fructification, so far as it is known, 

 composed of club-shaped, moniliform, radiating filaments, either 

 forming sessile warts, or arranged concentrically in little, stalked, 

 club-shaped bodies, terminated by pencils of delicate fibres. Grev. 



9. Desmarestia. Lamour. Desmarestia. 



Frond cartilaginous, plane or compressed, distichously 



branched, while young furnished with marginal deciduous tufts 

 of fine green filaments, the branches set with marginal spines. 



Grev. Alg. Frit. p. 36. t. 5 Named in compliment to A, G. 



Desmarest, a celebrated French naturalist. — The fructification 

 is unknown. 



1. D. ligidata, Lamour. (ligulatc. Desmarestia) ; frond elong- 

 ated plane with an obscure midrib 3 — 4 times pinnate, the pinna 



and pinnuhe opposite linear-Ianeeolate attenuated at the base 



Grev. Alg. Brit. p. 37. /. 5, — Sporochnus ligul., . \g. Sp. Alg, r. ]. 

 p. 158. — Desmia UguL, Lyngb. — Fucus Haul., Lightf. Sect. 

 p. 946. /. 29. Turn, Syn. Fuc.p. 99, Hist. 'Fur. t. 96. B. Boi, 

 t. 163(1. 



Principally on the southern and south-western shores of England. 

 Firth of Forth and Orkney, AVr. c. Clouston, Miltown Malbay, 



Inland, Mr. Harvey, ©. Summer. — Two to 5 or (i feet in length; 



colour a pale olive-green. Dr. Greville mentions Mr. Tamer's var, 

 dilatata, with the frond nearly 4 lines broad, as being (bond in Orkney 



i>\ Mr, Clous/ on. 



•J. D. nritlrdtii. Lamour. (aculeated Desmarestia) ; Btem short 

 rounded bearing numerous filiform flattened branches which are 

 again divided in ;i pinnated manner, the pinnules with dis- 

 tichous spines. -Grev. Alg. Brit p. 38. t. 5,f, 2, 3, s y rochnus 

 aculeatus, Ag, Sp, Alg, v, I. p, I.»l.— Desmia aculeata x Lyngb, — 

 Fucus (iiiilifitus. I. inn. Turn, Syn, Fur. p. 262, Hist, Fuc. 

 t. 187. /;. lint. t. 2445. 



