335 
Notes on New England Marine Alga. V. 
By FRANK S. COLLINS, 
Pleurocapsa fuliginosa, Hauck. This species I have found 
at Marblehead, Mass., forming a very thin reddish or brownish- 
black coating on rocks near high water mark ; probably it is to 
be found at similar stations elsewhere, as it occurs in most parts 
of Europe. The cells, which are from .005 to .02 mm. diam., 
are usually reddish-brown, but sometimes golden-brown or dull 
violet ; they are often united in twos, fours, or larger numbers, 
due to the repeated cell division in all directions ; when the cells 
cease to divide, the contents change into small round spores. 
The species is described and figured in Hauck, Deutschlands 
Meeresalgen, p. 515, fig. 231. 
Dermocarpa Schousbei (Thuret) Bornet. This species I have 
found at Nahant, Mass., growing on Rhodochorton Rothit and 
Rhizoclonium riparium , it is likely to be found also on other 
filamentous alge. The genus Dermocarpa differs from Pleuro- 
capsa in that the cells of the former do not divide, and therefore 
are not found united in twos, fours, etc., but though often closely 
packed, remain individually distinct, each attached to the host 
plant. In D. Schousbei they are spherical or flattened by 
mutual compression, and the color is light bluish-green. Figured 
and described, as Xenococcus Schousbei, in Bornet and Thuret, 
Notes Algologiques, p. 73, Tab. xxvi. 
_ Dermocarpa prasina (Reinsch) Bornet. Grows quite abund- 
antly in spring on the New England coast, on the older part of 
the fronds of Polysiphonia fastigiata. It is easily distinguished 
from the preceding species, the cells being cylindrical or club- 
shaped, .O15-.03 X .005-.02 mm., of a deep blue-green color. 
They are closely packed, forming cushion-like expansions. 
Reinsch described and figured in Contributiones ad Algologiam 
et Fungologiam, a number of species of Sphenosiphon, a genus 
which must give place to the older Dermocarpa; most of his 
species it would be practically impossible to distinguish. I do 
not think our plant can be separated from D. prasina, which 
occurs commonly in Europe on Catenella opuntia, and is figured 
and described in Bornet and Thuret, Notes Algologiques, p. 73, 
Tab. xxvi. 
