214 
Transactions of the Royal Society of South Africa. 
Helicodontium lanceolatum (Hampe & C. M.) Jaeg. George, CP., 1916 ; 
coll. H. A. W. (No. 541), c. fr. I have compared this with the type in 
Hampe's herbarium. The seta is only faintly scaberulous. The leaves 
are remarkably like those of Amhlystegium serpens (L.), only with numerous 
subquadrate alar cells. 
Dimerodontium africanum C. M. Near Cape Town, 1915 ; and George, 
CP., 1916; col. H. A. W. (Nos. 346, 561 p.p.), c. fr. ; King William's 
Town, CP., 1892 ; coll. Sim (No. 7116), c. fr. 
HOOKBEIACEAE. 
Cyclodictyon vallis-gratiae (Hampe) Broth. Kaapsche Hoop, Transvaal, 
1915 ; coll. H. A. W. (No. 334) c. fr. ; Hogsback, Tjumie, CP., 1917 • 
coll. D. Hend. (No. 359), c. fr. 
Htpoptbrygiaceae. 
Hypopterygium pennaeforme (Thunb.) Brid. Knysna, CP., 1916 ; 
coll. H. A. W. (No. 522). $ flowers are present, and the plant seems 
dioicous, as stated by Brotherus. Kindberg makes it monoicous. He also 
says the leaves are bordered with one row of cells ; here the border cells are 
mostly 2 -seriate. 
Leskeaceae. 
Lindbergia viridis Dixon sp. nov. (PI. XII, fig. 15.) 
Inter L. pseudoleskeoidem Dixon et L. haplocladioidem Dixon ludens ; ab 
ilia habitu graciliore, colore viridiore, foliis acutiorihus, costa tenuiorSy 
cellulis pellucidis ; ab hac colore, foliorum acumine multo hreviore, cellulis 
isodiametricis, etc. ; a L. patent folia Dixon nova sp., ex Africa tropicali, 
foliis minus patentihus, habitu multo graciliore, minus stricto, foliis minoribus, 
angustiorihus, costa paullo latiore, foliis perichaetialibus strictiorihus, areola- 
tione longiore, angustiore. E speciebus quattuor africanis gracillima. Seta 
brevis, 7-8 mm. alta, tenuis ; theca parva, anguste cylindrica. Peris tomii 
dentes pallidi, ligulato-lanceolati, superne parum angustati, dense grossius- 
cule papillosi, saepius, praecipue superne, papillis opaci. Endostomii mem- 
brana basilaris circa tertiam partem longitudinis dentium aequans, papillosa, 
subpellucida ; processus nulli. 
Hah. — Kaapsche Hoop, Transvaal, on wood, 1915; coll. H. A. W. (No. 
310). 
The most slender and delicate of the known African species, of which 
five have now been described. The following may serve as a key to these 
species : 
