
No. 2] NEW SPECIES OR FORMS OF MELOBESIEAE. 5 
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reminds one in habit of young specimens of a form of L. glaciale 
appearing in shallow water. Besides it now and then approaches 
L. phymatodeum in habit and even in regard to the conceptacles 
of sporangia. 
Occurrence. California: Pacific Grove, in low pools, Setchell, 
No. 1595 and 1596; Duxbury Reef, Marin County, in small pools 
in the rocks, Setchell, No. 1074 in part; and Puget Sound: Channel 
Rocks near Seattle, Wash., Setchell and Gardner, No. 654 
in part. 
Lithothamnion californicum Fosl. 
Five new calc. Alg. p. 3. 
f. microspora Fosl. mscr. 
Conceptacles of sporangia 200—300 p in diameter seen from 
above, occasionally not raised above the surface of the frond. 
The present species is shown to be rather varying and appears 
in two different forms rather analogous. to Lathothamnion laeve 
f. macrospora and f. tens, partly with large partly with small 
conceptacles of sporangia. The above f. mzcrospora characterizes 
itself especially thereby, that the conceptacles of sporangia seen 
from above are 200—300 p in diameter, thus smaller than in the 
typical form. They are partly subprominent partly not raised above 
the surface of the frond, in the latter case at least often caused 
thereby, that the sporangia for some reason are proportionally 
more slowly developed than the vegative part of the plant, such 
as now and then to be seen also in other species. 
The species stands between L. magellanicum and L. tenuis- 
simum, being very nearly related especially to the latter. It seems 
even to be a question whether this species ought to be considered. 
specificaliy distinct from the last named one, which till now is 
known only from the west coast of Africa. In habit it sometimes~ 
much reminds one of L. laeve. 
Occurrence. The form microspora known from Pacific Beach 
near San Diego, California, collected by Mrs. E. Snyder, comm. 
Mr. F. S. Collins; the typical form is met with in different places 
_ along the Pacific coast of America and northward to Puget Sound, 
