Ser. Rhodosperme^. Fam. CryptonemiacecB. 



Plate LXVIIL 



GIGARTINA PINNATA, a^. 



Gen. Char. Frond carnoso-cartilaginous, flat or cylindrical, simple or 

 variously branched, composed of two strata of cells ; the medullary 

 stratum, of cylindrical, articulated filaments, anastomosing into a 

 very lax network ; the cortical, of moniliform, vertical, dichotomous 

 filaments set in firm gelatine. Fructification : 1, external, globose, 

 finally perforate conceptacles, containing within a s,2iCC?itG, placenta (?) 

 formed of closely interwoven filaments, a compound micleus consist- 

 ing of many confluent nucleoli, or masses of roundish-angular spores ; 

 2, cruciate tetmspores, collected into dense, subprominent sori, 

 lodged bene?itli the superficial cells. — Gigartina [Lamour^, from 

 r^L^apTov, a grape-stone, which the conceptacles resemble. 



Frons carnoso-cart'daginea, plana v. cyUndracea, ramosa, ex stratis duohus 

 cellidarum composita ; stratum medullare ex fills temdbus cyUndraceis laxe 

 anastomosantlbus^ corticale ex fills mondiformlbus verticallbus dlchotonds 

 formatum. Fruct. : 1, favellidla intra pericarpiiim externum carpostomio 

 pertusum excepta, fills aracJmoideis intertextis obvuluta ; 2, tetrasporce cru- 

 ciatim divisa in soros subprominentes infra stratum corticale nidulantes 

 plurimce collecta. 



GiGARTiNA pinnata ; frond flattened, linear, decompound-pinnate ; pinnse 

 and pinnules distichous, linear-lanceolate, narrowed at the base and 

 apex, patent, obtuse; conceptacles sessile, marginal, depressed, um- 

 bilicate. 



G. pinnata; fronde complanata lineari decomposite pinnata ; pinnis pinmdisque 

 disticlds lineari-lanceolatls basi angustatis patentlbus obtusis ; cystocarpiis 

 sessilibus marginalibus depressls umbilicatls. 

 GiGARTiNA pinnata, /. Jg. Sp. Alg. v. 2. p. 270. Harv. Alg. Austr. Exsic. 

 n. 399. 



Hab. Port Phillip Heads, Malm., W. H. H. South Australia, Dr. Curdie. 

 Tasmania, Mr. Gunn. 



Geoge. Distk. Southern coasts of Australia. Tasmania. 



Descr. Root discoid. Fronds tufted, 1-2 feet in length, flattened, from i to 

 nearly i inch in breadth, twice, thrice, or four times pinnate. Finnce 

 and pi7inulce strictly distichous, issuing from the margin of the flattened 

 frond, unequal in size and development, large and small occurring inter- 

 mixed ; the larger 8-10 inches long or more. The pinnules are narrower, 

 somewhat thickened in the middle, but not cyhndrical : they vary much in 

 breadth and in shape, being sometimes broadly lanceolate and sometimes 



