10 M. FOSLIE. [1900 



Lithophyllum Phil. emend. 



Subgen. Eulitophyllum Fosl. 

 L. craspedium Fosl. 



New or crit. calc. Alg. p. 26; Calc. Alg. Funaf. p. 7. 



f. subtilis Fosl. mscr. 



Thallus as in f. abbreviata, but more delicate. Branches short, 

 crowded, terete or subcompressed, 2 — 3.5 mm. thick. 



This form in the main accords with f. abbreviata, but the 

 branches are only of about half the thickness of those in the latter 

 and several times thinner than in f. compressa. They are 2—3.5 

 mm. thick and in part rather compressed. I have seen but a soli- 

 tary specimen, and transitions probably occur. It is no doubt 

 a form of the above species, coinciding with this in structure as 

 well as the reproductive organs, but ought on the other hand to 

 be considered a denominated form. 



According to the label f. subtilis appears in lagoon platform 

 and shoals on Malepe Re, Funafuti. Herb. British Museum. 



L, subreduncum Fosl. mscr. 



Thallus forming small balls or irregular masses apparently freely 

 developed at the bottom, irregularfy branched, branches short, about 

 3 mm. thick, terete or subcompressed, verrucate and knotty, some- 

 what crowded and anastomosing, upwards often rather hooked, 

 with rounded ends, or occasionally almost truncate and depressed 

 in the centre. Conceptacles of sporangia forming very small convex 

 prominences or depressed point-like deepenings on the surface of 

 the branches, on a median-vertical section 300 — 375 ;j. in diameter. 



This species stands near to Lithophyllum fasciculatum and 

 almost fully coincides in habit with certain forms of the latter, 

 especially f. divaricata, about 3 — 5 cm. in diameter, and appears 

 like this to develop itself freely at the bottom. The branches are 

 however shorter and even more irregular than frequently in the 

 said species. Besides, it is plainly distinct in structure. The pith- 

 layer is on a median-longitudinal section composed of alternating 

 long and short cells, though not quite regular, the former 22 — 36 



