62 Verr Brecuer Wirrrock. 
Affinities and Differences. This species forms the connecting link between 
Pithophore isosporee and P. heterosporce. Besides the common cask-shaped spores, 
spores occur here of a cylindrical or almost cylindrical form. Inclosed spores of 
two kinds thus existing in P. Clveana nob., it might seem most reasonable to 
place the species among Pithophore heterosporee. The cause why I have not done 
so is l:o that P. Cleveana nob. evidently has its nearest relatives in the real Pitho- 
phore isosporce, and 2:0 that the cylindrical spores are so rare as to deserve being 
regarded merely as exceptions. — The most remarkable character in P. Cleveana 
nob. is its abundant helicoids. They are found in all specimens that are somewhat 
rich in branehes, and they are ‘not rare even in those poorer in branches. With 
LP. kewensis nob., which is rather nearly related to P. Cleveana nob., it has already 
(page 5d) been compared. From P. ocdogonia (Mont.) nob. and Pithophore hetero- 
sporveé it is distinguished by characters so evident as not to nead special mention. 
Sectio Il. PITHOPHORA HETEROSPOREA: 
Spores of several, dissimilar forms in each species; the inclosed 
of three forms, viz. cask-shaped, cylindrical and subirregular; the ter- 
minal as a rule of two forms, viz. cask-shaped and cylindrical, both with 
the upper end conical and the top somewhat rounded. (Species 6 
to 8). 
Species 6. Pithophora polymorpha nob. 
vxsicc. HOHENACK. Alg. mar. siec. 10:te Liefer., n:o 472 a; sub nomine Cla- 
dophora crispata Kiitz. 
Diagnosis: Principal filament of the cauloid part of the thallus in 
fertile specimens on an average 105 « thick, with branches of one or 
two degrees; branches of the first degree solitary or more rarely oppo- 
site in pairs; branches of the second degree solitary; spores solitary 
(rarely in pairs), partly inclosed, partly terminal; the inclosed spores in 
branches of the first, degree partly cylindrical, partly cask-shaped; the 
inclosed spores in the principal filament usually of an irregular shape; 
the cylindrical spores on an av. 63 w thick and 88 w long, the cask- 
shaped on an av. 104 w thick and 157 w long, the subirregular 121 « 
thick and 133 w long; the terminal spores commonly subconical with 
the top rounded, rarely cask-shaped with the upper end conical and the 
top somewhat rounded; the subconical spores on an ay. 63 w thick and 
155 w long, the cask-shaped on an av. 95 w thick and 148 w long. — 
Bll, igs. 13-7; pl: 4, fier 19. 
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