8 M. FOSLIE. 3 [1902 

Thallus 0.5—1 cm. thick, forming crusts on rocks, with irre- 
gularly wartlike or short branchlike, knotty, more or less crowded 
excrescences. 
As remarked in a pamplet in press!) I have considered a cal- 
careous alga from the Pacific coast of North America to be a stunted 
form of G. Brassica-florida (Harv.), being on the other hand un- 
certain whether the latter and G. mamullare are anything more 
than forms of one and the same species. 1 am still uncertain 
whether these species in fact are specifically distinct, as only rather 
young specimens of G. mamillare are known, a species which at 
any rate is closely connected with G. Brassica-florida. 1 am 
certainly most inclined to consider both identic, but at present | 
do not venture to unite them. So also in regard to the above f. 
litoralis. JI have seen but fragmentary and rather small pieces of 
this form, which seems to be rather varying. Besides the concep- 
tacles are emptied in the fertile pieces seen and, therefore, I am 
not quite sure of the nature of the reproductive organs and want 
to call attention to this form, although I am scarcely of any doubt 
at all in regard to its relation to the one or other of the said spe- 
cies. I refer it here to G. mamullare on account of the fact, that 
the latter with certainty is known only from America, where on 
the other hand any typical specimen of G. Brassica-florida has 
not yet been met with. 7 
The branchlike excrescences in f. lztoralis are a little thinner 
than in the typical form, partly rather densely crowded or 
almost confluent, partly somewhat scattered and then more 
irregular in shape and thickness. The conceptacles are often 
smaller than in G. Brassica-florida, but otherwise agreeing in 
shape. 
Occurrence. California: Point Fermin, San Pedro in hol- 
lows near highwater mark, Prof. Setchell, No. 1147; and 
Pacific Beach near San Diego, Mrs. E. Snyder, commie 
SCollimne: 

1) Die Lithothamnien des Adriatischen Meeres und Marokkos. — Wissensch. 
Mesresuntersuchungen. Abt. Helgoland. 
