Ser. Rhodosperme.e. Pam. Ceramiacea. 



Plate LII. 



GRIFFITHSIA BINDERIANA, Sond. 



Gen. Char. Frond filiform, dichotomous, articulated, monosiphonous, 



naked. Fructification : 1, involucrate favella, containing numerous 



angular spores; 2, tetraspores attached to the inner faces of invo- 



lucral ramelli, globose, triangularly parted. — Griffithsia (Ag.), in 



honour of the late Mrs. Griffiths, of Torquay, Devonshire. 



Frons filiformis, dicliotcma, articulata, monosiphonia, ecortieata. Fruct. : 1, 

 favellce involucratce sporas numerosas angulatas foventes ; 2 , tetraspores tri- 

 angule divisce interiore latere involucri, ramellis pluribus constituti seriates. 



Griffithsia Binderiana ; frond flabelliform, distichously much branched, 

 fastigiate ; branches cymoso-dichotomous, recurved, the minor divisions 

 unilateral; apices incurved; axils spreading; articulations subcylindrical, 

 scarcely contracted at the nodes, 2-3 times as long as broad ; fertile 

 ramuli on the inner side of the branches, solitary or secund, usually 

 of a single cell, crowned with an umbellate involucre enclosing nume- 

 rous tetraspores. 



G. Binderiana; fronde flabellata distiche ramosissime fastigiata ; ramis cymoso- 

 dichotomis recurvis, segmeutis minoribus secundis ; apicibus incurvis ; axillis 

 patentibus ; articidis cylindraceis ad genicida vix coniractis diametro 2-S-plo 

 longioribus ; ramulis fructiferis interiore latere segmentorum solitariis vel 

 secundis unicellidaribus, involucro umbellato tetrasporas numerosas amplec- 

 tente coronatis. 



Griffithsia Binderiana, Sond. PI. Preiss. v. 2. p. 168. Kiitz. Sp. Jig. 

 p. 660. ./. Ag. Sp. Alg. v. 1. p. 86. Harv. in Trans. R. I. Acad. v. 22. 

 p. 559; Alg. Exsic. Austr. n. 494. 



Hab. Parasitical on Zostera, and on various Algae, beyond tide-marks. 

 Swan River, Preiss ! Rottnest Island and Garden Island, Western 

 Australia, W. H. H., G. Clifton, Fsq. 



Geogr. Distr. Western Australia. 



Descr. Root a small disc. Fronds solitary or slightly tufted, 2-4 inches high, 

 as thick as hog's-bristle, perfectly distichous, repeatedly but not regularly 

 dichotomous, with a broadly flabelliform outline, the major and minor divi- 

 sions fastigiate. The principal ramifications are very patent, with a ten- 

 dency to produce dichotomous ramuli on the upper or inner faces of each 

 segment ; thus old specimens present a mixture of dichotomous and se- 

 cund ramification, resembling that of an irregular, somewhat scorpioid, 

 but much divided cyme. All the axils are patent ; the main branches are 

 frequently divaricate ; and the apices are very often incurved, and some- 

 times involute. The articulations are nearly cylindrical, and rarely exceed 



