Inter-Relationships of the Anacrogynce. 229 
allied to Symphyogyna than to any other genus, resembles Aneura 
in having the antheridia sunk in chambers separated from each 
other by partitions two cells in thickness, each chamber opening by 
a pore on the upper surface of the thallus—but the antheridia are 
not developed on special short branches as they are in Aneura. 
Again, Calycularia shows some resemblances to Morckia and Blyttia, 
e.g., in having a cupule-like scaly involucre in addition to a perianth, 
but in the structure of the sporogonium it agrees closely with the 
Codoniaceae. 
Although many of these resemblances are doubtless due to the 
occurrence of parallel developments, we may perhaps regard the 
Anacrogynae as having diverged along two lines, which we may call 
the “ Aneura line” and the “ Pellin line,” though these two genera 
have highly specialised sporogonia and are somewhat isolated from 
the genera with which we have classified them. In the Aneura line, 
ACROGYNAE 
Haplomitrium / 
I / 
Calobryum / Umbraculum 
including the Aneuraceae and Blyttiaceae, the most characteristic 
feature is the sterilisation of the central apical portion of the sporo- 
gonial tissue to form an incomplete columella or elaterophore; 
while in the Pellia line there is a corresponding basal sterilisation 
to form an elaterophore which projects upwards into the cavity of 
the capsule. That the elaterophore reaches its highest development 
in the genera Aneura and Pellia, while the vegetative structure of 
