136 Salmon. — A Monograph of 
herbarium. As regards the length of the excurrent nerve 
and the shape of the perichaetial leaves, I can find no differ- 
ence between Lindigii and ^S. latifolius. It may be noted 
that vS. Lindigii varies in size and also somewhat in habit; 
the stems are sometimes only a centimetre high, almost or 
quite simple, and of a rigid habit ; at other times, as is well 
seen in £ setiferusl the stems are more flaccid, much 
branched, and up to 4 cent. high. The most important 
characters, however, viz. the shape of the leaf, the strongly 
revolute margins, the characteristic areolation of hexagonal 
cells with pitted walls, the peristome with its long tube whitish 
at the base and divided above into sixteen nearly straight 
teeth each of which is split in its lower third into two filiform 
divisions, are found invariably in all the specimens, and I feel 
convinced that 5 . Lindigii , S. latifolius, and A. setiferus are 
names that have been given to one and the same well-marked 
species. The male plant does not seem to have been collected 
except in the case of the plant named 5 . latifolius in Mitten’s 
herbarium. 
The long arista, formed of the excurrent nerve, of the upper 
stem-leaves and perichaetial leaves is seen under a high 
magnification to be very minutely denticulate at intervals 
with subhyaline projections. The calyptra is truly mitrae- 
form, and is minutely asperous only towards the apex, and 
not anywhere setulose-hispid as is the calyptra of 6'. erythro- 
dontus and vS. clavipes. The stem in transverse section shows 
one or two peripheral rows of thick-walled cells, and is else- 
where composed uniformly of rather large polygonal cells 
with very thin and delicate walls, usually slightly and minutely 
thickened at the angles ; there is no ‘ central-strand/ The 
nerve shows in transverse section two ‘ pointer-cells ’ on the 
ventral surface, and on the strongly convex and projecting 
dorsal surface a well-developed band of stereid-cells ; there is 
a complete absence of * companion-cells.’ The superficial 
stomata at the extreme base of the capsule are few and 
scattered, with the long axis of the guard-cells sometimes 
parallel to that of the capsule, at others at right angles to it. 
