On the PiTHOPHORACEiE. 67 



pairs), partly inclosed, partly terminal; the spores of the branches partly 

 cask-shaped, partly cylindrical; the spores of the principal filament of 

 an irregular shape; the cask-shaped spores on an av. 152 ^i thick and 

 226 ^i long, the cylindrical on an av. 83 /.i thick and 143 ß long, the 

 irregular 191 /.i thick and 213 fi long; the terminal spores partly obovoïd 

 witb the base truncated, partly (and more rarely) subconical with the 

 top rounded; the obovoïd spores on an av. 150 ^ thick and 212 ^i long, 

 the subconical on an av. 88 ^ thick and 246 ^ long. — Plate 1, figs. 

 18—20; pi. 5, figs. 11 and 12. 



[P. robusta, filo priiicipali partis tlialli cauloideœ specimiuum fertilium circa 

 165 fi crasso, ramos trimn ordiiium emitteute; ramis ordiiiis primi teruis verticil- 

 latis; ramis ordiuis secundi et tertii solitariis Tel biuis oppositis; sporis solitariis 

 (raro geminatis), vel iuclusis, vel teriniualibus ; sporis ramorum vel orculajformibns 

 vel cylindricis ; sporis till principalis forma subirregiilari ; sitDris orcnlœformibus c:a 

 152 /J,, crassis et 226 f.i lougis, cylindricis c:a 83 ß crassis et 143 ß longis, subirre- 

 gularibus c:a 191 ß crassis et 213 ß longis; sporis terminalibus vel obovoideis basi 

 truncata, vel rarius subconicis apice rotundato; illis c:a 150 |tt crassis et 212 /t longis, 

 his 88 ß crassis et 246 ß longis.] 



Locality. This species grows in India near Tranquebar in fresh water. The 

 locality is thus given by EoTl-i 1. c: »In aquis stagnantibus Tranquebariœ lecta a 

 Cel. EOETTLERO»; and by KÜTZING in Phyc. geuer. 1. c. thus: »Aus See^ümpfen 

 bei Tranquebar in Ostindien. Januar 1799: Klein (Herb, berol. — unter n:o 431).» 



General Description. Fertile specimens. This species is distinguished at 

 the first glance by a stronger ramification and more robust growth than the other 

 species. The cauloïd part of the thallus has, as a rule, branches of three 

 degrees. Those of the l:st degree are generally placed three and three (once I 

 have even seen* four) in a whorl on the principal filament. Now and then, espe- 

 cially near to the lower end of the principal filament, single branches are found, 

 which are very strongly developed. The branches of the 2:d and 3:rd degree are most 

 frequently single, or two and two opposite to each other. Sometimes I have, how- 

 ever, found the branches of the 2:d degree -placed three in a whorl, like those of 

 the l:st. The branches are attached to. their supporting cells a small space below 

 their top, as in the other Pitli02)]wracc(e. This space varies as to length, but is 

 always shorter than the diameter of the lowest brauch cell, and sometimes so short 

 as to be hardly discernible. Branchless cells are very rare in the principal fila- 

 ment, except the subsporal ones; they are somewhat more frequent in the branches 

 of the l:st and 2:d degree, though the number of branchless cells is always much 

 less than the number of those supporting branches. Accessorial basal branches are 

 not rare (pi. 1, fig. 18). Rather seldom the top cells develop, in or near their top, 

 handlike helicoïds, such as pi. 5, fig. 11 and 12 shows. — The spores can be formed 

 both by the top cells and by the other cells, both by those of the principal filament 

 and by those of the branches. The terminal spores are of two different shapes. 

 Either — and this most frequently — they are swollen, and have then a short. 



