Laing. — Observations on the Fucoideae. 309 



green, parasitic, filiform, irregularly branched, proliferous, solid, 

 with distinct stern and branches, but no bladders or leaves. 

 Conceptacles scattered over the whole frond under the surface, 

 containing linear-obovate spores, and simple paranemata." 

 {Specific:) "Fronds 3-8 inches long, growing from the con- 

 ceptacles of Hormosira, excessively branched, bushy, cylindric ; 

 branchlets narrow, spindle-shaped, axis of solid interwoven 

 filaments, periphery of radiating coloured filaments." 



This is undoubtedly a true parasite, as it is never found 

 elsewhere than on Hormosira banksii. It generally grows out of 

 one of the conceptacles of its host, but occasionally out of the 

 solid portion of the stem, when it never penetrates deeper than 

 the cortical tissue. True parasitism is very rare among the 

 Fucoidecs. One or two cases in the Phceosporca are mentioned by 

 Decaisne and Le Maout. This is the only one with which I am 

 acquainted amongst the Fucacea. 



Reproduction : The plant is dioecious. I have not seen the 

 male conceptacles ; and here it may be noticed that, in all the 

 New Zealand Fucacea, female specimens are very much more 

 plentiful than the male. The female conceptacle contains un- 

 branched hairs ; but there are no long hairs surrounding the 

 aperture of the conceptacle. The oogonia are developed in the 

 ordinary way ; but the number of oospheres in each oogonium 

 appears to vary from about 7 to 11 ; but, as I have had no 

 opportunity of examining fresh specimens of this plant, I am 

 not quite sure about this point. Fig. 6 shows several oogonia. 



Hab. In tidal pools, on Hormosira ; not uncommon, to some 

 extent sporadic. 



12. Hormosira banksii. 



This has been fully described by Mr. Mollet. ("Trans. N.Z. 

 Inst.," 1880, Art. xxxix.) 



13. Splachnidium rugosum. 



Description in Hooker's Handbook (Generic :) " Eoot, a disk. 

 Frond olive-green, cylindric, proliferously branched ; branches 

 saccate, full of mucilage and branched filaments ; walls thin, 

 membranous. Fruit dioecious. Conceptacles scattered over the 

 whole surface of the frond, attached to the inner surface of its 

 walls, spores linear-oblong, subsessile, paranemata simple." 

 (Specific :) " Fronds, 4-8 inches high. Main axis stout, cylindric 

 or club-shaped ; -J inch in diameter ; branches sac-like, truncate, 

 1-2 inches long, surface covered with mamilla?, each furnished 

 with a pore that opens into the spore cavity beneath." 



The stem consists of an epidermal tissue of small coloured 

 cells surrounding a mass of mucilage, into which protrude a 

 number of long branched hairs. The top of the growing stem 

 is covered with a slight down, composed of very peculiarly- 

 shaped colourless hairs, made up of a number of cells which are 



