Ser. Melanospermk.k. Fam. Chordariacea. 



Plate XLVIII. 

 ADENOCYSTIS LESSONII, Hook, filet Harv. 



Gen. Char. Root scutate. Frond membranous, bag-like, hollow or filled 

 with water, coated externally with a velvety stratum of minute, ver- 

 tical, club-shaped, articulated filaments. Spores pyriform, affixed to 

 the superficial filaments. — Adenocystis (Hook.fil. and Harv.), from 

 aSrjv, a gland, and kvcttls, a bladder ; because the bag-like frond is 

 marked with gland-like dots. 



Radix scutata. Frons membranacea, saccata, intus cava v. aqua repleta, punctis 

 glandulceformibus conspersa, extus strato tenui velutino filorum clavatorum om- 

 nino velata. Sporce pgriformes, adfila peripherica affixes. 



Adenocystis Lessonii, Hook. fii. and Harv. 



Adenocystis Lessonii, H.fil. and Harv. Fl. Antarct. v. 1. p. 179. t. 69./. 2. 

 J. Ag. Sp. Jig. v. 1. p. 124. Harv. Alg. Austr. Exsic. 



Asperococcus Lessonii, JBorg, in Bup. Fog. p. 199. t. 11./. 2. Grev. Syn. 

 p. xlii. Endl. Gen. Suppl. v. 3. p. 26. 



Chorda Lessonii, Kntz. Sp. Alg. p. 549. 



Hab. On tidal rocks. At Port Arthur, Tasmania, W. H. H. 



Geogr. Distr. Abundant throughout the Antarctic regions, as at Cape Horn ; 

 Kerguelen's Island ; Auckland and Campbell Islands, and at Cockburn's 

 Island, lat. 64° S. — Bory, Dr. Hooker, etc. 



Descr. Root a small, scutate disc. Frond 1-3 inches high, rising from a short, 

 filiform stem, obovoid or pyriform, inflated, hollow and empty, or filled 

 with sea-water, of a firmly membranous or coriaceous texture. It is subject 

 to very little variation of form. The membrane is formed of two strata of 

 cells, of different sorts ; the inner stratum being composed of several rows 

 of large, multangular, hyaline, mostly empty cells ; the outer of several rows 

 of extremely minute, densely packed, coloured cellules, firmly connected to- 

 gether. The membranous frond, thus organized, is further clothed exter- 

 nally with a continuous, velvety pile of very minute, vertical, clavate, arti- 

 culated filaments ; and here and there marked with hemispherical gland-like 

 spots, from which byssoid filaments (sometimes) issue, and which may pos- 

 sibly be connected with the antheridia. The spores are pyriform, on little 

 stalks, immersed among the peripheric filaments, to whose bases they are 

 affixed. The colour of the frond is a very dark brown, the substance firm 

 and coriaceous, and the plant scarcely adheres to paper in drying. 



A curious Alga, more nearly allied to the European Chorda 



