52 



Veit Breciier Wittrock. 



Sterile specimens are of the same dimensions as fertile ones. 



Affinities and Differences. This species has a near relative in P. kewensis 

 nob. The differences are as follows (not counting the considerable difference as 

 to size, P. cequalis nob. being' twice as big as P. kewensis nob.): the inclosed 

 spores are in P. cequalis nob. proportionally less swollen and. shorter than in P. 

 kewensis nob.; the spore-bottoms are rounded in P. cequalis nob., but abrupt in 

 P. kewensis nob.; the spores are branchless in P. cequalis nob., in P. kewensis nob. 

 they often support brandies; the rhizo'fd is in P. cequalis nob. generally only rudi- 

 mentary, in P. kewensis nob. it consists of one whole cell; not to mention several 

 smaller differences. P. cequalis nob. is less nearly related to P. sumairana (v. 

 Mart.) nob. The differences are noted under P. sumatrana (v. Mart.) nob. 



3. Pithophora kewensis nob. 



Exsice. Wit TE. & Nordst. Alg. Exsicc. Fasc, I, n:o 39. 



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

 fertile specimens on an average 59 thick, with solitary branches 

 of only one degree (rarely of two); spores single, partly inclosed, 

 partly terminal; the inclosed spores cask-shaped, but more elongated, on an 

 av. 81 (<( thick and 205 /i long; the terminal spores cask-shaped with 

 the upper end conical and the top somewhat rounded, on an av. 88 /i 

 thick and 219 (x long; the rhizoid part of the thallus as a rule unicel- 

 lular. — Plate 1, fig. 8; pi. 2, figs. 1 — 12; pi. 3, figs. 1 — 9; pi. 4, figs. 

 2—11; pi. 5, figs. 9, 10. 



[P. gracilis et elongata, filo prineipali partis thalli cauloidere speciminum fer- 

 tilium circa 50 p, erasso, ranios primi solius ordinis (raro secundi etiam ordinis) so- 

 litaries emittente ; sporis solitariis, vel inclusis vel terminalibus; sporis inclusis elon- 

 gato-orculseformibus, c:a 8f crassis et 205 /i longis; sporis terminalibus orcuhe- 

 formibus, sursum brevi-acuminatis, apice subrotundato, c:a 88 /i crassis et 219 fi 

 longis; parte thalli rhizoidea plerumque unicellular!.] . 



Locality. P. kewensis nob. is found by me in the Tropical Aquarium or the 

 so-called Waterlify-house at Kew in England. 1 ) It was found with spores during 

 my whole sojourn there, from the 3:rd to the 25:th of August 1872. — As is men- 

 tioned before, I think that the plant is introduced here from a tropical country, 

 probably from South America. (See on this par. 7, pag. 46, 47.) 



General Description. Fertile specimens. Caulo'id part of the thallus. 

 This part is always branched, though sometimes but slightly. In general the cells 

 only of the principal filament develop braoches; all the branches are then of the 

 list degree. Sometimes the branches of the Est degree, especially the lowest 

 ones, develop branches of the 2:d degree, though mostly but few. Regard- 

 ing the different strength and nature of the branches of the list degree, 

 the following 6 types may be distinguished. In the Est type the branches are 



*) I think it worth inquiry, whether plants belonging to this order may not be found 

 also in aquaria for tropical plants on the continent. 



