250 Dixon: NEw MosseEs FROM MALAY PENINSULA 
ligerum, though it may there also be only 1 cm. long. The 
principal difference, however, lies in the perichaetial leaves; 
in A. cuculligerum they are slightly denticulate only; here the 
whole acumen is densely fringed with long, almost ciliolate 
teeth. The seta, as in A. cuculligerum, is set, in the upper part 
with flat, sub-discoid thickenings, such as are found here and 
there in various genera, e. g., in several species of Meiothecium; 
it would seem desirable to have a suitable term for these; and 
I suggest tentatively the terms platypapillae, platypapillose. 
Acroporium leucophyllum Dixon sp. nov. (PLATE 4, FIG. 6) 
Sat robustum, peralbidum; caulis longe repens, irregulariter 
pinnatus, ramis nunc brevioribus, subobtusis, plerumque e/onga- 
tis, rigidiusculis, valde attenuatis, ad 3 cm. longis, caudiformibus. 
Caulium et rami cortex nigricans, inter folia albida valde conspi- 
cuus. 
Folia saepe spiraliter seriatim disposita, erecta, erecto- 
patentia vel saepe rigide divergentia, lanceolata, ab insertione 
fere paullo angustiore sensim angustata, valde concava et pro- 
funde carinata, longiuscule stricte anguste acuminata, marginibus 
infra subrecurvis, ad basin acuminis explanatis, acumine ipso 
argute denticulato fortiter late recurvis, unde acumen dorsaliter 
subconvolutum. Folia apicem versus ramorum sensim magis 
magisque minora, angustiora. 
Cellulae _peranguste dineares, parietibus tenuibus, dorso 
apicibus ispide papillosae, infra vix mutatae 
sed laeves, inferne aurantiacae, alares circa trinae vesiculosae, 
intense purpureae, opacae. Cetera ignota. 
H wood, Gunong Tahan, Pahang, July 1911; Ridley 
(1032). 
A very distinct and striking species, both in habit and the 
white colour, and in the structure of the leaves. A. asperifolium 
(Thw. & Mitt.) is perhaps the nearest, but is greener in colour, 
and the leaves, much less papillose at back, are very longly and 
gradually tapering and of quite different form. A. ruficaule 
is quite different in size, habit and colour. 
The form of the acumen is rather remarkable; as in many 
species with concave leaves (Trichosteleum, Chaetomitrium, 
&c.) the base of the acumen is flattened out at the margins, 
with the centre hollowed out and subcucullate; but higher up in 
