Dixon: NEw MosseEs FROM MALAY PENINSULA = 251 
the acumen the margins become widely revolute, so as almost 
or quite to meet at the back, rendering the back of the acumen 
subtubular, a very unusual feature. 
The long, attenuated branches would appear to be pendulous. 
The rather small, deep purple auricles contrast very strongly 
and prettily with the narrow, pale, lamina cells 
The spiral arrangement of the leaves comes out rather strik- 
ingly when dry, in more than one way. On some branches the 
leaves are rigidly divergent and little altered when dry, in which 
case they give the appearance of a spiral herring-bone arrange- 
ment. At other times the leaves of each spiral become accumbent 
on one another, and the resulting strand is twisted spirally 
round the branch, in a funicular manner, not, however, crowded 
as in Grimmia funalis and many species of Macromitrium, but 
distantly, so that the black cortex of the branch shows distinctly 
and prettily in contrast with the white leaves. (I have tried to 
depict one of these branches on PI. II. fig. 6b). Frequently, on 
the other hand, the spiral arrangement is not at all manifest. 
Acroporium obscurum (Broth.) Dixon sp. nov. (Sematophyl- 
um obscurum Broth. MS. in sched.) (PLATE 4, Fic. 7) 
Dioicum. Sordide viride. Habitus et folia fere A. rufi 
formarum robustiorum, ramis saepe elongatis, flexuosis. Folia 
rigide patentia, saepe homomalla, superiora plerumque J/eniter 
falcato-secunda, \anceolato-subulata, e basi fere convoluta, apice 
tubulosa, stricta acuta sed haud valde attenuata, integra, superne 
dorso plerumque (praecipue superiora) rugosa-papillosa. Cel- 
lulae parietibus valde incrassatis, porosis, obscurae. 
Flores & numerosi, majusculi, caulini. Perichaetium majus- 
culum, bracteis angustis, internis erectis, sensim in subulam 
piliformem, flexcuosam, quam laminam saebe multo longiorem, 
grosse dentatam, attenuatis, 3 mm. fere longis. Seta usque ad 
3 em. alta, laevis. Theca immatura solum visa 
HAB. Lohore, Aug. 1908; Ridley (sine numero); det. Broth- 
erus. Penang Hill, Pulau Penang, 1896; Ridley (538) in herb. 
Mitten; det. H. N. D. Oto Jungle, Upper Sarawak, Borneo; 
Ridley (sine numero) in herb. Mitten; det. H. N. D. 
The foliation is very much that of robust A. rujum or the 
smallest forms of A. secundum, but the fruiting characters are 
quite different; the long, quite smooth seta separates it from 
