Phycologia australica; or, A history of Australian sea weeds ..and a synopsis of all known Australian Algae .. . k. The sticJiidia are more con-tantly in the axils, and are falcato-fusiform, simple, tufted, containing asingle row of tetraspores. The colour is a brilliant crimson, becomingbrighter in fresh-water. The genus Plocammm, which has but one representative in thenorthern hemisphere, has many southern species, distributedchiefly in AustraUa and South Africa. Of these the present isa beautiful and readily known and abundant species, differingfrom most of the Australian kinds in having se
Phycologia australica; or, A history of Australian sea weeds ..and a synopsis of all known Australian Algae .. . k. The sticJiidia are more con-tantly in the axils, and are falcato-fusiform, simple, tufted, containing asingle row of tetraspores. The colour is a brilliant crimson, becomingbrighter in fresh-water. The genus Plocammm, which has but one representative in thenorthern hemisphere, has many southern species, distributedchiefly in AustraUa and South Africa. Of these the present isa beautiful and readily known and abundant species, differingfrom most of the Australian kinds in having sessile conceptacles,and ramuli alternating in threes, not in twos. In both thesecharacters it agrees with the cosmopolitan P. coccineum, fromwhich it is readily known by the warted conceptacles and denti-culate edges of the ramuli. Fig. 1. Plocamium Preissianum,—tJie natural size. 2. Part of a pinna, withconceptacles. 3. Vertical section through a co/^cp^ifaeZe and branch. 4. Partof a pinna with axillary stichidia. 5. Three of the sticJddia A tetraspore:—the latter figures variously Ser. Rhodosperme^. Fam. Gelidiacece. Plate LXIV. EUCHEUMA SPECIOSUM,/.^y. Gen. Char. Frond shrub-like, carnoso-cartilaginous, horny when dry,spiny or tubercled, solid, composed of three strata; the medullarystratum, of densely interwoven, elongated, anastomosing, longitudinalfilaments; the intermediate, of several layers of roundish, angularcells, gradually smaller outwards; the cortical, of minute, colouredcellules set in radiating filaments, at right angles to the axis. Frnc-tification: 1, coticepfacles subglobose, sessile on the ramuli, contain-ing, within a very thick pericarp, a central placenta (becoming hollowin the middle), to which tufts of spore-threads are attached; sporesseriated or solitary, oblong or subpyriform; 2, zonate ietraspores,immersed in the cortical stratum.—Eucheuma (/. J^.), from ev,intensitive, and x^^f^^^ ^^^^^ ^^V ^^ melted; because the specie
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Keywords: ., bookauthorharveywi, bookcentury1800, bookdecade1850, bookyear1859
