58 Vkit Bkkciikr Wittrock. 



Ohs. Havino- i)l)taini><l malorial lor examination of this species 

 (bv the mediation, as has 1)L'0ii nieiitiouod bef(n-e, of I):r .1. Iîostakixski), 

 when a great part of the essay was ah-eady [trinted, and having thus 

 been unable to give due attention to the morpliohigical peeuHarities of 

 this species in the general account of the morphology of the order, 

 I may I'o permitted to give in this place an exposition of its most essen- 

 tial mnrphological peculiarities. They are l:o that J\ oeiUn/onia (Mont.) 

 11(^1). is the only one among F. isosporeœ that has the system of ramifica- 

 tion of the cauloïd so strongly developed as to possess regularly branches 

 of three degrees; 2:o that the rhizoid part of the thallus sometimes 

 attains so strong a development that it forms branches of two degrees ; 

 3:o 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:o that the mother-cells of the spores have often the 

 power of forming not only one spore, but successively even two ; ') 

 o:o that the spores formed in the normal manner, remaining attached 

 to the mother specimen, sometimes germinate in the same maimer as 

 tlie prolific cells, i. e. by developing a branch from one ol' their sides 

 (or sometimes a branch from each of its two sides). 



5. Pithopliora Cleveana nob. 



Dingn.oHiK. Principal filament of the cauloïd part of the thalhis 

 in fertile specimens on an average 75 /( thick, with bi-auches 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 a, longitude 216 ^i ; the terminal spores 

 cask-shaped with the upper end conical and the top somewhat rounded, 

 on an av. 93 ^ thick and 232 f.i long. — Plate 2, figs. 13 — 15; pi. 4, 

 figs. 12—18; pi. 5, figs. 1—8. 



[P. terrestris subgracilis et siibbrevLs, filo prineipali partis tlialli caiiloidefc 

 speciminum fertilium circa 75 /i crasso, raiuos i)leruin(iue uuius .solum ordinis, in- 

 terduni autem duorum, singulos vel raro biiio.s opposiios emittente; raniis ce]hili.s licli- 

 coideis sœpe prœditis; sporis vel inclusis vel teruiinaHbus, solitaviis (raro geuiiuatis); 

 sporis inchisis subelougato-orculjutbniiibus vel ravius .subcylindricis, illis c:a 102 ft 



') In the peculiarities iiidieated in tlic points .3 and 4, P. ocdot/ouia (Mont.) nob. 

 shows a not ineonsiderable eonfuniiity with Z''. Zclliri (v. Mart.) noli, amollir 1'. lirlr- 

 rosponcc. 



