Ser. RiiodospermEjE. Fam. Rhodomelacece. 



Plate XLII. A. 



POLYZONIA INCISA, J. a 9 . 



Gen. Char. Stem filiform, articulated, polysiphonous. Ramuli distichous, 

 alternate, plano-coinpressed, leaf-like, entire on the lower edge, toothed 

 or pectinato-partite on the upper, transversely zoned with hexagonal 

 cells. Fructification : 1, ovate ceramidia, containing a tuft of pear- 

 shaped spores ; 2, lanceolate stichidia, simple or crested, supra-axillary, 

 pedicellate, containing large tetraspores in a single row. — Polyzonia 

 (Suhr), from iro\v<i, many, and %a>vr), a band. 



Caulis filiformis, articulatiis, polysiplionius ; ramuli distichi, alterni, plano-com- 

 pressi, foliiformes, deorsum integerrimi, sursum varie dentati v. pectinato-par- 

 titi, transversim zonatl, cellulis hexagonis. Fruct. : 1, ceramidia ovata, fasci- 

 culum sporarum pyriformium continentia; 2, stichidia lanceolata scepe crislata, 

 supra-axillaria, tetrasporas magnas singula serie evolutas foventia. 



Polyzonia incisa ; primary surculus creeping ; stems erect, simple or pin- 

 nate ; ramuli (or leaves) pectinato-partite on the upper edge, lacinise 

 4-5, lanceolato-linear, acute, areolate, the cells in three rows; ceramidia 

 ovate, nearly axillary; stichidia crested, supra-axillary, erecto-patent. 



P. incisa ; surcido repente ; caulibus erectis simplicibus v. pinnatis ; ramulis (v. 

 foliis) sursum pectinato-partitis, laciniis 4-5 lunceolato-linea ribus acutis areo- 

 latis, cellulis oblongis triseriatis ; ceramidiis ovatis ex lachiula prima foliorinii 

 formatis ; sticJiidiis cristatis supra-axillaribus adscendentibus. 



Polyzonia incisa, /. Ag. in Linn. v. ]5. p. 24. Harv. Ner. Auslr. p. 71 ; 

 Alg. Exsic. Austr. n. 144. 



Hab. Parasitical on Fucoids, and on Gelidium glandulafolium, etc. Port 

 Fairy, plentiful, W. H. H. S. Australia, Br. Curdle, Dr. Mueller. 

 Tasmania, R. Gunn, Dr. Lyall. 



Geogr. Distr. South coast of Australia, and Tasmania. 



Descr. Primary frond prostrate, rooting at the nodes, creeping over other Algae. 

 From this there rise several erect stems, h inch to 1 inch long, simple or 

 alternately pinnate, articulate ; the articulations scarcely so long as broad, 

 composed of six cells surrounding a central cavity. Hamuli alternate, 

 horizontally patent or somewhat recurved, pectinate on the upper side; 

 the laciniee 4-5, somewhat lanceolate, tessellated with three rows of hexa- 

 gonal, oblong cells. Capsules broadly ovate, subsessile, formed from the 

 lowest segment of the fertile ramulus, and thus nearly in the axil ; the 

 pericarp areolated, thin, and containing a dense tuft of pyiif'orm spores. 

 Stichidia lanceolate, suberect, supra-axillary, more or less crested at the 

 summit, containing a single row of large tripartite tetraspores. Colour 

 a deep full red, becoming brighter in fresh-water. Substance somewhat 

 cartilaginous but soft. In drying the plant adheres to paper. 



A pretty species, intermediate in character between Polj/zonia, 



