Laing. — On Neiv Zealand Species of Cerarniacese. 387 



Genus 1. Spermothamnion (Areschoug). 



Thallus filamentous with creeping rhizoids attached by 

 haptera, and erect more or less distichously oppositely or alter- 

 nately branched fertile shoots. Sporangia placed on the lateral 

 branches of the erect shoot, singly or in groups, divided into 

 tetrads. Antheridia rounded, placed on the upper sides of the 

 lateral branches. Cystocarps terminal in groups, tightly en- 

 closed by the involucral branchlets, without pericarp. The 

 fruit-mass consists of 2 paired united gonimoblasts, which are 

 stout and small, with slightly convex loosely woven upper 

 surface, from which the external cells spread out radially and 

 subsequently produce large oval spores. 



I have introduced the generic description because I have 

 seen specimens apparently belonging to this genus, from the 

 Sumner Estuary, Dunedin, and Dusky Sound, but the material 

 has been insufficient for the proper definition of the species. 



Genus 2. Ptilothamnion (Thuret). 



Thallus filamentous, rhizoids provided with holdfasts and 

 upright paripinnate (more seldom alternately branched) thallus. 

 Sporangia generally terminal on the pinnules, divided into 

 tetrads. The antheridia and procarps in exactly similar situa- 

 tions. Antheridia oval or elongated. Cystocarps terminal, en- 

 closed in an involucre of a few involucral branchlets, appearing 

 as very small oval tightly closed heads with a single very small 

 stoutish gonimoblast ; from this rounded surface the scanty 

 external cells are only partially disengaged, and then subse- 

 quently ripen into spores (in basipetal sequence). 



1. Ptilothamnion schmitzii (Heydrich, " Berichte der Deutschen 

 Botanischen Gesellschaft," vol. xi., 1893). 



Thallus carmine-red, J-l mm. high, carpeting Zonaria sin- 

 clairii (Hook, and Harv.), composed of monosiphonous filaments, 

 which remain naked. The first filaments are creeping, 20-30 /x 

 broad, fastened by means of short holdfasts to the substratum ; 

 secondary branches upright, simple, seldom branched, 16-20 ^ 

 broad. Cells half as long again to twice as long as broad. Pro- 

 carps either sessile on one-celled secondary filaments, or upon a 

 one- or two- celled stalk on the first or second cell of the filament, 

 overarched by 1 short bent covering ramulus, and consisting of 

 4 carpogonia. The cystocarps, which are attached similarly to 

 the procarps, are small, rounded, and contain in a colourless 

 pericarp 28 to 30 carpospores. They are overarched by a single 

 large covering-branch. Antheridia are composed of oval bodies 

 at the point of a secondary filament, and have an articulated 

 filamentous axis. Sporangia solitary or in pairs on one- or two- 



