GRIMMIACEAE. 169 
I have based the following arrangement principally upon my own study 
of the plants themselves. Mr. W. Gray, of Mauriceville, has for some years 
furnished me with ample collections, mostly of the catia species ; while 
Dr. Brotherus has kindly put at my disposal his rich collection, mostly 
collected by the late W. Bell; and I have a good many of Beckett’s 
collecting, for which I am indebted to the Rev. C. H. Binstead and Mr. D. 
Petrie. So far as these specimens go (and they number some hundreds) 
they do not at all bear out Brown’s conclusions as to the large number of 
New Zealand species, and there is no doubt that he relied too much on 
characters which cannot be held of specific value. 
Certain characters which have been used as the basis of specific 
descriptions are of less value than formerly supposed. The length of the 
seta and the degree of exsertion of the capsule has its value, but may easily 
be overrated. The colour of the calyptra, and to some degree its hairiness 
or otherwise, are also liable to lead to error if too implicitly relied on, as 
is also the degree of striation of the capsule in certain species. Among 
the most reliable characters are the stomata on the capsule-wall, the form 
of the exothecium cells, and the minute structure of the peristome. 
The structure of the capsular stomata is of first importance. In one 
group (Gymnoporus) these are superficial, lying between and practically 
flush with the outer layer of exothecium cells ; the stomata are therfore 
fully exposed to view. In the other group (Calyptoporus) the stomata lie 
below the outer layer, and are more or less covered by a ring of surrounding 
exothecium cells, which are not flat as usual, but are protuberant above the 
level of the capsule-wall ; in this case the guard-cells of the stomata are 
almost or quite con neealed. The stoma in the immersed form may be 
compared to a minute volcano, with the guard-cells and stoma lying 
at the er of the crater (cf. Plate IX, figs. 5 and 6). 
erms “immersed ”’ and “ exserted,”’ of the capsule, are frequently 
rather loosely used. I have endeavoured to employ them with a gr reater 
degree of precision, as they are of considerable importance, as follows :— 
Immersed, when the a ender! (when moist) reach to or very 
nearly to the top of the caps 
Emergent, when they reach above is base but not nearly to the top 
of the capsule. 
Ezserted, when they reach approximately to the base of the capsule. 
Fully exserted, when the capsule base is well above the upper leaves. 
a rule the capsules appear more exserted in the dry state than when 
moist, owing to the leaves iieg somewhat twisted and therefore less erect ; 
but this is not always the case 
I have used the term “processes” for the teeth of the inner 
peristome, rather than “ cilia,” the term in frequent use, as they are by no 
means homologous with the cilia of the Bryoid and Hypnoid peristome, but 
rather with the processes, being alternate with the outer teeth. These 
Ene are often very — and fragile, and the peristome must not 
be to y assumed to be single simply because they are not easily 
fowad? On the other hand, it happens that in several of the New Zealand 
species the processes are unusually broad as compared with those of most 
of the European species 
