Dixon: NEw MosseEs FROM MALAY PENINSULA 257 
leaves themselves, however, not lying in that plane); and in the 
coarse, rigid, wide subula, instead of the long, piliform flexuose 
‘one of H. pycenophyllum. 
That species has usually been placed in Sematophyllum 
(Acroporium), but is transferred to Warburgiella by Fleischer, 
with one or two species of somewhat near alliance. This has 
necessitated the widening of the generic character, especially 
in regard to the calyptra, which as the genus is defined by C. 
Mueller is campanulate or mitriform, not cucullate. The genus 
as enlarged appears to me rather ill-defined, and I should be 
inclined to keep it restricted as by C. Mueller. 
Hypnum pycnophyllum is placed by Brotherus with about a 
dozen species more or less allied, under the Section Chaetomitri- 
ella (C. M.). Some of these certainly, as S. palanense (Hampe) 
and S. bistrumosum (C. M.), and others less clearly, appear to 
me better placed in Trichosteleum than in Acroporium. The 
small group to which H. pycnophyllum, the present and following 
two species belong, is however perhaps best kept in Acroporium. 
Acroporium malayanum Dixon sp. nov. (PLATE 4, FIG. 16) 
A. pycnophyllo (C. M.) and A. cuspidatifolio (Fleisch.) affine; 
ab illo cellulis multo latioribus, 6-8 yu latis, opacioribus, incras- 
satis, dorso superne plus minus spiculosis, foliis angustioribus, 
minus cito, brevius, minus flecuose, subulatis, ramisque obtusis 
differt; ab hoc ramis plus minus complanatis, cellulis opacioribus, 
marginalibus haud diversis, apice prominente, spiculoso, sine 
papillis mediantis. 
Dioicum. Planta mascula solum visa. 
HAB. Botanical Gardens, Penang, 1915; Binstead (57). 
Very near to A. pycnophyllum, but that species has more 
concave, wider leaves, less spreading, more abruptly contracted 
into a long, flexuose piliform arista, the cells there are much 
narrower, thin-walled, pellucid, and smooth at back. The cells 
here are decidedly incrassate, much wider, and opaque with the 
cell contents. 
Warburgiella cuspidatifolia Fleisch., of which I have seen no 
specimen, has leaves, from the description, of a similar form, 
-but the marginal cells are there shorter and differentiated from 
the inner, and the upper cells have a strong papilla in the 
middle of the lumen; in the present species it is the apices of the 
cells alone that are prominent and spiculose. 
