58 Veir Brecuer Wirrrock. 
Obs. Having obtained material for examination of this species 
(by the mediation, as has been mentioned before, of D:r J. Rostarinskn), 
when a great part of the essay was already printed, and having thus 
been unable to give due attention to the morphological peculiarities of 
this species in the general account of the morphology of the order, 
I may be permitted to give in this place an exposition of its most essen- 
tial morphological peculiarities. They are l:o that P. oedogonia (Mont.) 
nob. is the only one among P. isosporew that has the system of ramifica- 
tion of the cauloid so strongly developed as to possess regularly branches 
of three degrees; 2:0 that the rhizoid part of the thallus sometimes 
attains so strong a development that it forms branches of two degrees; 
3:0 that the subsporal cells are often so rich in protoplasmatic contents, 
that they have the power of developing one, and now and then even 
two, branches; 4:0 that the mother-cells of the spores have often the 
power. of forming not only one spore, but successively even two; ') 
5:0 that the spores formed in the normal manner, remaining attached 
to the mother specimen, sometimes germinate in the same manner as 
the prolific cells, i. e. by developing a branch from one of their sides 
(or sometimes a branch from each of its two sides). 
5. Pithophora Cleveana nob. 
Diagnosis. * Principal filament of the cauloid part of the thallus 
in fertile specimens on an average 75 w thick, with branches commonly 
of only one degree, but now and then of two; branches as a rule soli- 
tary (rarely opposite in pairs); helicoid cells pretty common; spores 
single (rarely in pairs), partly inclosed, partly terminal; the inclosed 
spores cask-shaped or more rarely subcylindrical; thickness of the cask- 
shaped spores on an av. 102 uw, longitude 216 w; the terminal spores 
cask-shaped with the upper end conical and the top somewhat rounded, 
on an av. 93 w thick and 232 w long. — Plate 2, figs. 13—15; pl. 4, 
figs. 12—18; pl. 5, figs. 1—8. 
[P. terrestris subgracilis et subbrevis, filo principali partis thalli cauloidez 
speciminum fertilium circa 75 w crasso, ramos plerumque unius solum ordinis, in- 
terdum autem duorum, singulos vel raro binos oppositos emittente; ramis cellulis heli- 
coideis seepe preeditis; sporis vel inclusis vel terminalibus, solitariis (aro geminatis); 
sporis inclusis subelongato-orculeeformibus vel rarius subeylindricis, illis c:a 102 w 
1) In the peculiarities indicated in the points 3 and 4, P. ocdogonia (Mont.) nob, 
shows a not inconsiderable conformity with P. Zeller’ (v. Mart.) nob. among P. hete- 
rosporce. 
