10 M. FOSLIE. [1899 



branches. Conceptacles of sporangia subprominent, 300 — 400 in 

 diameter. 



Tlie specimens tliat I have seen are 3.5 — 4.5 cm. in diameter 

 by a height of 2 — 3.5 cm. Tiie crust appears frequently to be 

 feebly developed, attaining a thickness of up to about 0.7 mm. 

 and no considerable extent. It sends forth densely crowded, in 

 old specimens repeatedly divided, subdichotomous branchs^^stems. 

 The branches are short, terete or subcompressed, 1.25 — 1.75 mm. 

 thick, fastigiate, especially in the lower parts much anastomosing. 

 The ends are rounded, here and there thickened. 



The conceptacles of sporangia are somewhat prominent, seen 

 from above 300—400 p- in diameteter, the roof flattened in the 

 central parts and here ti^aversed by about 20 muciferous canals. 

 The sporangia are unknown. 



In a longitudinal median section of a branch are to be seen 

 regular and distinct, more or less cup-shaped layers of tissue. The 

 cells are commonly about twice as long as broad, with rather thin 

 Avalls, or 12 — 22, frequentty 15 — 18 p- long and 7 — 10 p. broad. 



The species stands between L. hracliycladum and L. falsel- 

 lum, especially somewhat approaching the latter in habit, but also 

 reminding one of delicate forms of Lithopliyllum racemus. 



It is only known from Chaloup bay, I^ernando do Noronha 

 (Brazil), Ridle}^, Lea and Ramage, according to specimens in Bri- 

 tish Museum. 



Perhaps is L. f asciculatum Mob.'^) from Bahia referrible to this 

 species, although the ramification seems to be somewhat different. 



Lithothamnion falsellum Heydr. 



in Ber. d. deutsch. bot. Ges. Bd. 15. Pag. 414. 



f. genuina. 



Lithothamnion falsellum He3'dr. 1. c. 



f. plicata Fosl. mscr. 



In Ber. d. deutsch. bot. Ges. Bd. 15, Pag. 61 is described an 

 alga under the name of LitJiophyllum Marlothii Heydr. This 



1) M. Mobius. Bearbeitung der von H. Schenck in Brasilien gesammelten 

 Aloen. Hedvvigia. Bd. 28. 1889. Pag. 309. T. XL, fig. 14. 



