On the Sorns of Dipteris. 
?43 
or sometimes two present in the latter species. Fig. 14 was drawn 
from a specimen, labelled “China Station,” from the collection of 
Captain Hope, R.N. This is probably an example of Dipteris 
quinquefnrcnta. In any case it shows characters of outline and sori 
intermediate between Dipteris hijurcata and Dipteris conjugatei. An 
examination of its sori showed that all the sporangia of a sorus were 
apparently of the same age, but material was not available for 
developmental observations. 
Fig. 14. Dipteris quhiquefurcata Baker (?) pinnae showing greater width 
upwards; below, the sori are in two lateral series, but spread out upwards 
with many fissions. 
From the facts thus obtained it appears that the three species 
form a series, of which Dipteris bifurcata is the most primitive. 
This species shows the distribution of sori typical of Matonia. 
There appears to have been first a widening of the pinnules in 
