48 Veit. Brecher Wittrock. 



pliologically, not physiologically) rhizoïd part, developed from 

 the g-erminated spore downwards, almost always sterile and 

 branchless, commonly unicellular. Spores neutral, quiescent 

 (agamo-hypnospores), generally cask-shaped, single, formed by 

 division into two of the cauloïd cells, of the chlorophyll-filled 

 and commonly widened upper parts of these cells; in germi- 

 nating as a rule dividing into two cells, the one giving rise 

 to the cauloïd and the other to the rhizoïd part of the thallus. 

 [Pitliophoraceœ nob. Algaï (aquœ dulcis) chlorophyllaceae, clado- 

 phoroideae, e seriebus cellularum bipartitione cellulae terminalis genitis 

 exstructœ. Thallus a duabus partibus distinctis constitutus: l:o parte 

 cauloidea, e spora germinata sursum evoluta, propagativa, semper (fere) 

 ramosa, ramis e cellulis suffultoriis pauUo infra apicem egredieutibus ; 

 2:o parte (morphologice non phj^siologice) rhizoidea, e spora germinata 

 deorsura evoluta, semper fere sterili et simplici, plerumque unicellulari. 

 Sporee agamete, quiescentes (= agamo-hypnosporfe), sœpissime orculas- 

 formes, solitariae,, bipartitione cellularum partis thalli cauloideœ formatai; 

 (cellulœ singulje, matres sporarum, parte superiore tumefacta et contente 

 chlorophjdlaceo farcta, sporas singulas et cellulas singulas steriles sub- 

 sporales gignunt). Sporse germinantes in binas plerumque cellulas divisée, 

 cellula altera in partem thalli cauloideam, altera in partem thalli rhizoïdeam 

 denique evoluta.] 



GENUS PITHOPHORA nob. 

 Character the same as that of the order. 



Sectio I. PITHOPHOE^ ISOSPORE^: 



Spores all of the same principal form in each species; the in- 

 closed either cylindrical or cask-shaped, the terminal either cylindrical 

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

 (Species 1 to 5). 



Species 1. Pithophora siimatrana (v. Mart.) nob. 



Synon. Cladophora swnaUana v. Mart. Die Tange, pag. 20, pi. 2, fig. 2. 



Diagnosis : Principal filament of the cauloïd part of the thallus in 

 fertile specimens on an average 127 ,a ^) tliick, with branches only of the 



*) The numbers in the diagnoses are all average numbers, gained by com- 

 parison of a great number of measurements. 



