194 Transactions of the Royal Society of South Africa. 
thecii rete firmum, cellulis orificium versus seiisim minoribus, subincrassatis. 
Spori 16-20 /x, laeves. 
jEr<x&.— Eagle's Nest, Bloemfontein, Dec, 1916 ; coll. Prof. Potts, comm. 
Sim (No. 8663). 
This appears from the foliage to belong to Didymodon (subgenus 
Didymodon sensu stricto, Limpr.), and being gymnostomous is allied to 
D. afer CM., but differs widely from that species, inter alia in the leaf 
apex, which while little narrowed is usually acute or subacute, rarely 
rounded. It many respects it resembles very closely the smaller forms of 
the European D. tophaceus (Brid.), which, however, is peristomate and has 
not the scabrous nerve of the present species. 
Didymodon afro-ruhellus Broth. & Wager (Broth. MS. in litt. ad H. A. 
Wager). (PI. XI, fig. 6.) 
Subgenus Erytheophyllum Limpr. Habitu B. rubelli (Hoffm.), sed 
multo minor, tenerrimus, caules vix 1 cm. alti, gracillimi, flexuosi. Folia 
patentia, sicca flexuoso-incurva, 1"25-1*75, rarius 2 mm. longa, e basi parum 
latiore late lingidata, ohtusiiiscula, apiculata, marginibus hie illic leniter 
refiexis vel suhplanis, integris vel apice irregulariter obscure sinuatis ; costa 
validiuscula, rufescens, in apiculum pallidum mucroniformem excurrens, 
superne dorso minute scaberula. Areolatio perdensa, opaca, e cellulis 
minutis, densis, rotundo-quadratis, dense minute papillosis instructa. 
Cellulae basilares abrupte elongatis, anguste rectangulares, seu lineares, 
tenues, hyalinae, marginales seriebus nonnullis minores, chlorophyllosae, 
limbum basin fere attingentem formantes. Seta pallide rubra, hrevis, circa 
6 mm. longa, tenuis, flexuosa ; theca minuta elliptica, operculo conico brevi, 
rostellato ; exothecium leptodermicum, pallidum, e cellulis breviter late 
rectangularibus instructum. Peristomium fragile, e dentibus brevissimis, 
angustissimis, rubellis, dense papillosis, basin versus in membranam brevis- 
simam cohaerentibus. 
Hah.— Yan Eeenen Pass, coll. H. A. W. (No. 79). 
Resembles J), rubellus in miniature, but with wider, shorter, widely 
pointed obtuse leaves, which are not denticulate at summit, but at the most 
obscurely sinuate or notched. 
Barhula pilifera Brid. Cape Town ; coll. H. A. W. (No. 362 Us). Port 
Murray, King William's Town, CP., 1893 ; coll. Sim (No. 7323). 
B. torquescens Schimp. Table Mt., coll. P. Webster, comm. C Webster 
(No. 332), c. fr. 
Tortilla atrovirens (Smith) Lindb. In innumerable forms as regards 
size, shape of leaves, size of cells, development of peristome, etc. ; Cape 
Town; coll. H. A. W. (Nos. 547, 556, 557), c. fr. ; Moorddrift, Waterberg 
District, Transvaal, 1916 ; coll. H. A. W. (No. 409), c. fr. T. recurvata 
Hook., albeit very distinct in appearance from the ordinary European form, 
is without any doubt to be referred to this species. 
