Scr. KiioDospp^RMEiT.. Yam. Corcillinacea:. 



Plate CCXXXT. 



AMPHIROA GRACILIS, iiarv. 



Gen. Char. Frond terete, compressed, or flat, calcareous, articulated, di- 

 cliotomous, pinnated or whorled. Nodes cartilaginous. Fruct. : 1, 

 conccptacles conical, wart-like, sessile on the disc of the articulations, 

 furnished with an apical pore, and containing in the base of the 

 cavity a tuft of erect, pyriform, at length four-parted spore-threads. — 

 Amphiroa [Lamour.], a fanciful mythological name. 



Frons calcarea, fragiUs, teres v. compi'essa v. plana, artlculula, dlchotoma v. 

 pbinatim ramosa v. vei'ticillatu. Genlcula cartllaginea. Fr. : 1, coriceptacula 

 conica, verrucaeformia, ad superficiem articulonun sessilia, apice poro pertum, 

 in f undo locidifila sporifera fasclcidata erecta demiini quadripartitajfoventia. 



Amphiroa gracilis ; frond elongate, terete, slender, di-trichotomous, fas- 

 tigiate ; joints cylindrical, equal, truncate at the base and apex, all 

 very long, 10-14 times as long as broad ; nodes naked, as long as 

 broad ; ceramidia very numerous, directed to all sides. 



A. graciUs ; fronde elongata tereti tenui di-trichotoma fastigiata ; articulia 

 cylitidraceis (pqualibus basi et apice truncatis omnibus longissiniis dlametro 

 10-14-y!?^o lovgioribiis ; genicuUs nudis diametro aqualibus ; cej'amidiis nii- 

 merossimis quoquoversis. 



Amphiroa gracihs, Harv. in Trans. R. I. Acad. v. 22. p. 547. Haro. Jig. 

 Ex sic. A list r. n. 459. 



Hab. King George's Sound and Rottnest Island, common, W. II. H. 



Geogr. Distr. Western Australia. 



Descr. Fronds tufted, 3-4 inches high, trichotoraous or rarely dichotomous, 

 occasionally some of the main divisions whorled. Branches cylindrical, 

 slender; lower as well as upper articulations many times longer than their 

 diameter, cylindrical and equal, truncate at each end, or but little incras- 

 sated. The nodes are short throughout ; in the larger brandies they are 

 about as long as broad, in the lesser ones much shorter, and in the ultimate 

 divisions inconspicuous. Cystucarps prominent, tubercular, formed not only 

 on the upper, but on the medial and often on the lower articulations, closely 

 placed and directed to every side. The colour, when recent, is a full pur- 

 ple, becoming pale-red or white after death and on exposure. The substance 

 is very brittle, and the frond does not adhere to paper in drying. 



This appears to be a common form in Western Australia, and 



