188 MR. E. 8. SALMON ON THE GENUS NANOMITRIUM. 
nately kept up the unnatural Tribe Cleistocarpe in his classifica- 
tion. Nanomitrium and Ephemerum are placed there in the Order 
Ephemeracee ; the former will now have to be removed, as the 
Order is characterized by possessing a capsule "stets ohne 
Andeutung eines Deckels." 
It is even doubtful if Limpricht can include Nanomitrium in 
the Cleistocarpe at all, as this author expressly states as the 
most important charaeter of the Cleistocarpe, "dass die... 
Kapsel sieh niemals mittelst eines Deckels öffnet, auch wenn 
dieser der Anlage nach vorhanden ist.” 
But we ean safely, I think, put aside the idea that either 
Nanomitrium or Ephemerum will find a permanent place in the 
Cleistocarpe ; for the maintenance of this tribe leads to the 
obviously unnatural separation of such genera as Physco- 
mitrium and Physcomitrella. We need consider, therefore, only 
those schemes of classification in which cleistocarpous genera 
are considered as being composed of degraded or simpler forms 
belonging to various stegocarpous Orders. Nanomitrium has 
already been well placed by Lindberg (2) in the Funariacee. 
The possession of a rudimentary lid further justifies the 
position of this genus in an Order in which stegocarpous genera 
occur, and tends to give it a place near PAyscomitrella, as in 
that genus (which has been generally regarded as cleistocarpous) 
Mrs. Britton (9) has lately recorded a regular dehiscence of 
the capsule. 
From the preceding remarks it is clear that Ephemerum and 
Nanomitrium are too closely allied to be separated in different 
Orders. This has been felt by many authors. Limpricht, for 
instance, includes both in Ephemeracee; Paris, in his ‘Index 
Bryologicus ' (10) has even sunk Nanomitrium in Ephemerum. 
Lindberg wavered as to the proper systematic position of Ephe- 
merum. At first (3) this author placed it in the section /unariee of 
Funariacee, but later (2. p. 410) wrote :—“ Ephemerum vix inter 
Funariaceas est collocandum, sed potius inter Poftiaceas in serie 
Tortulearum (9) " ; and finally, in the classical * Musei Scandi- 
navici’ (4), we find Ephemerum placed in the Tortulacee and 
associated with Barbula. 
Braithwaite (11) has followed Lindberg as regards the placing 
of Ephemerum in Tortulacee, but considers that its affinity 
appears to be greatest with the genus PAascum, “both in the 
calyptra and areolation." 
