Laing. — On Netv Zealand, Species of Ceramiaceae. 393 



sibly not be specifically distinct from the following one, as both 

 species seem to vary considerably, but they are distinct enough 

 in their extreme forms. 



Both plants require much fuller investigation and description 

 than they have yet received. 



2. Pleonosporium hirtum, R. M. L. (= Cattithamnion hirtum 

 (partim), Hook, and Harv., Fl. Antarctica, 192, t. 78. i. 2). 

 Plate XXVIL, fig. 1. 



Thallus a dull purple-lake, tufted, 8 to 10 cm. high, irregu- 

 larly alternately pinnately branched in all directions. Main 

 stem often short or altogether wanting, the base sparingly 

 coated with minute cells. Its articulations from 400-500 /m in 

 length and 1 50-250 /j in breadth. It and the main branches 

 are coated by decurrent rhizoids from the terminal cells of 

 the pinnae. The pinnae are alternate and bi- or tri-pinnately 

 branched, with cells intermediate in character between those 

 of the rachis and terminal pinnules. The pinnules, excepting 

 those near the apices, are long and filamentous, with cells of 

 varying size and shape, and sometimes six to eight times as long 

 as broad. These filaments are woven together into an inex- 

 tricable network of small mesh covering about two-thirds of the 

 entire surface of the plants, the ends of the pinnae in older speci- 

 mens alone being free from it. The plant is thus not so com- 

 pletely covered by the network as P. brounianum. The apices 

 of the pinnules are free for the length of from 1-2 mm., and beset 

 the plant on all sides, thus giving the plant that furry or shaggy 

 appearance to which it owes its name. The apical pinnules 

 often di- and sometimes tri-chotomously divided at their tips, 

 and several often coalesce longitudinally to form a single branch. 

 This perhaps gives rise to the veined appearance referred to by 

 Harvey. The cells of these pinnules are from 60-80 /x long and 

 30-40 /.<. broad. Thev form penicillate masses completely sur- 

 rounding and extending beyond the main growing-point. Spor- 

 angia of the Pleonosporium type, in series on the pinnules. 

 Antheridia and cystocarps unknown. 



Distribution.— St. Clair (J. C. S.f) ; Lyttelton (R. M. L.). 



I am probably not wrong in identifying this plant with 

 Harvey's Callithammon hirtum, with which it corresponds ex- 

 actly in general appearance and vegetative structure. Harvey, 

 however, in his drawings shows tetraspores divided into tetrads ; 

 but this, I think, is to be explained by the fact that his species 

 probably included not only Pleonosporium hirtum, P. brounia- 

 num, but perhaps also the Spongoclonium to which I have given 

 the name S. pastorale. In my own collection there is a young 

 plant bearing sporangia, collected at the same time and place as 



