1919.] The Sixth Indian Science Congress. clix 
cribed by the writer some years ago. This genus is extremely 
interesting in that it shows a close relation with the widespread 
its body; the air-chambers, pores, scales, stalk, receptacle, 
capsule-wall and elaters. There can hardly be any doubt 
that, like the dorsal position of the stalk, these different struc- 
tures are derived from more complex ones and the plant is a 
direct descendant of Hxormotheca. The short stalk and the 
very shallow groove are particularly interesting as they definite- 
ly show the transition from a stalked toa sessile receptacle 
along with the disappearance of the groove, while the dorsal 
the decrease in the size of the seta. As a matter of fact it is 
an all-round reduction. In view of the transitional nature of 
the plant referred to the genus Stephensoniella between the so- 
called Marchantiaceae and the so-called Corsiniaceae it is not 
justifiable to keep the latter as a distinct fami 
The last stage in this series would be the total suppression 
of the involucre and a further reduction of the sporogonium. 
organs are not in groups but scattered singly and in this respect 
s 
