Laing. — On Neiu Zealand Species of Cerarniaceie. 389 



The " axile tetraspores " (tetrachocarpiis axillaribus) does not 

 agree well with the terminal tetraspores in my plant. Indeed, 

 the New Zealand species seems to come close to the British 

 Ptilothamnion pluma (see also under Antithamnion ptilota). I 

 have, however, retained Montagne's specific name. This course 

 is scarcely likely to cause confusion, and so it seemed un- 

 necessary to describe the plant as new. I have therefore also 

 accepted provisionally Agardh's identification. 



Genus 3. Griffithsia (C. Agardh). 



Thallus erect, pinnately or dichotomously branched. The 

 branches are composed of single rows of large cylindrical cells, 

 which are often expanded in the centre and constricted at the 

 nodes, thus becoming cask-shaped. They are naked or provided 

 with delicate ramuli arranged in whorls, which bear axile spor- 

 angia. These, in consequence of the obliteration of the point 

 of the shoot, sometimes appear terminal, and the ramuli thus 

 form an involucre consisting of fertile or partly of fertile and 

 partly of sterile branchlets. The sporangia are divided into 

 tetrads. The antheridia are thickly packed together or are 

 arranged analogously to the sporangia tightly packed together 

 or in somewhat loose bundles. Procarps terminal on special 

 sometimes abbreviated or rudimentary branchlets, and deve- 

 loped out of 2 or 3 of the terminal' joint cells of the shoot. 

 The cystocarps terminal on shortened frequently quite abbre- 

 viated shoots, with an involucre of ramuli. The fruit-mass 

 consists of 1 seldom of 2 gonimoblasts, collected into a single 

 mass, or more generally divided into several successively de- 

 veloped gonimolobes. Almost all of the cells of the gonimolobes 

 produce spores. 



A genus of 20-30 species, found chiefly in the warmer seas. 

 Typical species are G. corallina (C. Agardh), G. setacea (G. 

 Agardh). 



1. Griffithsia sonderiana, J. Agardh. Chief synonymy : G. son- 

 deriana, J. Ag., Epicr. Florid., p. 62. G. setacea, Harv., 

 Handbook of the N.Z. Flora, p. 709. Callithamnion grif- 

 fithsioides, Harv., Phvc. Austr.. pi. 160. G. {?), comosa, Grun. 

 " Novara," p. 62, pi. x. Plate XXV., fig. 1. 



The plant consists of masses of closely packed rather flaccid 

 more or less irregularly dichotomous filaments. Dichotomy 

 takes place about once every centimeter, or at every fourth or 

 fifth cell. Branches fasciculated, fastigiate, 10-15 cm. long, and 

 in dried specimens 1 mm. in diameter. In fertile specimens 

 below the apices appear a number of short lateral compound 

 ramuli. more or less irregularly disposed, sometimes secund, at 



