POTTIACEAE. 119 
Like the E. verticillatum of Europe, E. irroratum appears to prefer a wet 
calcareous substratum, and the stems are usually encrusted at the base 
with calcareous matter. 
After careful examination I am very reluctantly obliged to conclude 
that Tetracoscinodon R. Br. ter. must be referred here. A glance at the 
The peristome in £. irroratum consists of short, very irregular teeth, 
broad at the base and often practically united there, very thin and 
t 
respects precisely identical with the smaller forms of E. irroratum) shows * 
the articulations much more rectangular than figured—precisely, indeed, 
as figured by Brotherus (Engl. & Prantl, Musci., p. 401). As regards (5), 
this is no doubt a striking feature, and one which, were it constant, 
Gulliverii R. Br. ter., which must also be referred here. 
TricHostomum Hedw. 
This formerly most comprehensive genus has now been whittled down 
until none of the New Zealand species formerly referred to it can be allowed 
to remain. It will probably be found useful to indicate briefly the present 
position of plants formerly placed here. 
Handb. N.Z. Fi. :— 
T. leptodum Mitt. = Thysanomitrium. 
T. lingulatum H. f. & W. = Didymodon. 
T. phaceum H.f. & W. = Tortula. 
T. mutabile = Weisia viridula. 
T. rubripes Mitt. = Tortella. 
T. laxifolium H.f. & W. = Ditrichum flexifolium. 
T. elongatum H.{. & W. = Ditrichum. 
T. setosum H. f. & W. = Ditrichum flexifolium. 
_T. australe Mitt = Ditrichum strictum. 
(R. Br. ter. in Trans. N.Z. Inst., vol. 29, pp. 478 et seq.) 
T. faleatum R. Br. ter. = Dicranum aucklandicum. 
