178 cryptonemiacej:. v. 



Frond two to three feet long, six to ten inches wide, rising with a short stem 

 which soon dilates into a simple, lanceolate lamina, jagged and irregularly dentate 

 at the margin, and rough all over both surfaces, with short simple or forked spines. 

 Substance thin, but coriaceous when dry. Colour a fine purple. Conceptacles formed 

 towards the base of the lamina, in the marginal or discal spines. 



Nearly allied to G. Eadula, but much thinner in substance. 



7. GiGARTiNA Eadula, J. Ag. ; frond stipitate ; stipes somewhat channelled, 

 simple or branched ; the branches expanding into thick, fleshy, flat, oblong, ovate, 

 elliptical or obovate entire laminte, which are either naked or densely muricated with 

 papilliform processes, in which the conceptacles are imbedded. J. Ag. Sp. Alg. 2, 

 p. 278. G. papiUata,Harv. in Beechey {not of Ag.) Mastocarpus corymbifents, Kiitz. 

 Sp. Alg. p. 734. Fucus bracteatiis, Turn. Hist. t. 25. 



Hab. North West Coast, it/t^ns-zes. Calihvma,, Douglas ; Coulter, Capt. Pike, (v. v.) 



Fronds (in the Californian specimens) six or twelve inches long or more, three to 

 four inches wide, cuneate or slightly channelled at the base, obovate, obtuse or sub- 

 acute, sometimes ovato-lanceolate, thick, carnoso-coriaceous, the upper half more or 

 less densely echinate on both surfaces, with mamilliform, acute or obtuse, simple or 

 multifid processes. Colour a dark brownish red. A very variable species, common 

 in the Southern hemisphere and on the Pacific coasts. The Californian specimens 

 which I formerly referred to G. papillata, Ag. are pretty constantly obovate and 

 quite simple, obtuse, tapering much to the base ; but some are lanceolate, and one 

 is very irregular in shape. At the Cape of Good Hope, where this species is pro- 

 fusely common, many forms occur together ; some having perfectly simple fronds ; 

 others dividing near the base into many segments, or secondary fronds, each of 

 which is stipitate, ovate, obovate or lanceolate. In others each segment is deeply 

 bifid, and in others the frond is somewhat palmate. Specimens bearing tetraspores 

 are quite smooth, destitute of papillae. 



On a careful comparison of the Californian specimens on which Kiitzing's Masto- 

 carpus corymbiferus is founded, with numerous specimens of G. Radula collected at 

 the Cape, I do not see how they are to be distinguished : and this opinion is formed 

 from aa examination of a much fuller suite of specimens than Kiitzing, to whom I 

 communicated those which he describes, liad before him. 



X. IRIDJEA. Bory. 



Frond gelatinoso-carnose, flat, subsimple, composed of two strata of cells ; the 

 medullary stratum of cylindrical, articulated filaments, anastomosing into a veiy lax 



