354 Howe: ALGAE OF BERMUDA AND THE BAHAMAS 
In an old cistern, on Sound Shore Road, Bermuda, A. B. 
Hervey, December, 1920; also Jan. 15, 1921. 
Pithophora heterospora, though belonging to Wittrock’s 
section “ Pithophorae Heterosporeae’’ and more heterosporous 
than any of the species that he refers to that section, shows 
points of contact with P. oedogonia (Mont.) Wittr., of his section 
“‘Pithophoreae Isosporeae.’’ It resembles P. oedogonia in the 
usual great development of the rhizoid part of the thallus and 
its slight differentiation from the cauloid part. In fact, with 
the chlorophyll content of the two parts nearly the same and with 
both parts producing spores in nearly equal abundance, it is 
sometimes difficult to assert with confidence which is the cauloid 
end and which the rhizoid. In distal and median cauloid parts 
the spores have about the same form and arrangement as in P. 
oedogonia, though smaller (156-182 u X 68-80 uw. vs. av. 230 u 
X 114 u). But in the rhizoid and proximal cauloid parts the 
spores are often more nearly spherical, we believe, than in any 
previously described species and also are often in more extended 
chains, in one case as many as twenty-two being counted in a 
single unbroken concatenate series. So far as we discover, three 
spores in a series are the most that have hitherto been described. 
In our material, preserved with formalin, there are in the 
cells, lying in the protoplast or extruded from it and lying between 
it and the cell wall, numerous irregular heric dark-colored 
bodies, which in the older cells and fie spores take the form of 
flocculent or substellate flecks. We have not noted these bodies 
in dried specimens of other species, but do not know whether 
they are really characteristic of Pithoephera heterospora or may be 
due to mode of preservation or to transitory physiologic condi- 
tions. These bodies do not respond to the customary micro- 
chemical tests for oil. 
Pithophora heterospera is associated with Oedogonium con- 
sociaium Collins & Hervey, which. grows epiphytically upon it, 
in some parts densely clothing it with young filaments or with 
encrusting masses of attached spores, as was the case with the 
type of the O. consociatum, which was described from Bermuda 
as occurring on Pithophora kewensis (but figured, in contradiction 
of the text, on Rhizoclonium). Closterium moniliferum Ehrenb. 
also accompanies the Pithophora in profuse abundance. 
