On THE PITHOPHORACEA. 67 
pairs), partly inclosed, partly terminal; the spores of the branches partly 
eask-shaped, partly cylindrical; the spores of the principal filament of 
an irregular shape; the cask-shaped spores on an av. 152 w thick and 
226 w long, the cylindrical on an av. 83 w thick and 143 w long, the 
irregular 191 w thick and 213 w 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 w thick and 212 w long, 
the subconical on an av. 88 w thick and 246 w long. — Plate 1, figs. 
18—20; pl. 5, figs. 11 and 12. 
[P. robusta, filo principali partis thalli cauloidee ‘speciminum fertilium circa 
165 w erasso, ramos trium ordinum emittente; ramis ordinis primi ternis verticil- 
latis; ramis ordinis secundi et tertii solitariis vel binis oppositis; sporis solitariis 
(raro geminatis), vel inclusis, vel terminalibus; sporis ramorum vel orculeeformibus 
vel eylindricis; sporis fili principalis forma subirregulari; sporis orculeformibus c:a 
152 w crassis et 226 w longis, cylindricis c:a 83-u crassis et 143 w longis, subirre- 
gularibus c:a 191 w crassis et 213 mw longis; sporis terminalibus vel obovoideis basi 
truncata, vel rarius subconicis apice rotundato; illis c:a 150 w crassis et 212 w longis, 
his 88 w crassis et 246 w longis.} 
Locality. This species grows in India near Tranquebar in fresh water. The 
locality is thus given by RoTH I. c: »In aquis stagnantibus Tranquebariz lecta a 
Cel. ROETTLERO»; and by KUrzine in Phye. gener. 1. ¢. 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 
the first glance by a stronger ramification and more robust growth than the other 
species. The cauloid part of the thallus has, as a rule, branches of three 
degrees. Those of the I: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 i:st. The branches are attached to their supporting cells a small space below 
their top, as in the other Pithophoracee. 'This space varies as to length, but is 
always shorter than the diameter of the 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 1: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 (pl. 1, fig. 18). Rather seldom the top cells develop, in or near their top, 
handlike helicoids, such as pl. 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, 
