On the PitpiophoracetE. 



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 ^ thick and 

 226 (i long, the cylindrical on an av. 83 (x thick and 143 ^ long, the 

 irregular 191 p, thick and 213 fi long; the terminal spores partly obovoid 

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

 top rounded; the obovoid spores on an av. 150 fi thick and 212 /_i long, 

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

 18—20; pi. 5, figs. 11 and 12. 



[P. robusta, filo principali partis thalli cauloidea3 sped minimi fertilium circa 

 165 fx crasso, ramos trium ordinum emittente; ramis ordinis prinii ternis verticil- 

 latis; ramis ordinis secundi et tertii solitariis vel binis oppositis; sporis solitariis 

 O'aro geminatis), vel inclusis, vel terminalibus; sporis ramorum vel orculseformibus 

 vel cylindricis; sporis fili principalis forma subirregulari ; sporis orculseformibus c:a 

 152 [i crassis et 226 /.i longis, cylindricis c:a 83 fi crassis et 143 ,« longis, snbirre- 

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

 truncata, vel rarius subconicis apice rotundato; illis c:a 150 p crassis et 212 (.i longis, 

 bis 88 p crassis et 246 ,u longis.] 



Locality. Tbis species grows in India near Tranquebar in fresb water. Tbe 

 locality is thus given by Roth 1. c: »In aquis stagnantibus Tranquebarise lecta a 

 Cel. Roettlero»; and by KUTZING in Phye. gener. 1. c. thus: »Aus Seesiimpfen 

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



General Description. Fertile specimens. This species is distinguished at 

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

 species. The cauloi'd 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 Pithophordce.ee. This space varies as to length, but is 

 always shorter than the diameter of tbe lowest branch 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, tig. 18). Rather seldom the top cells develop, in or near their top, 

 handlike helicoi'ds, 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, 



