1912] DEUTSCH—TARGIONIA 490 
Classification 
The Marchantiaceae are at present classified according to three 
schemes. LerITGEB (1) gives the following: 
Marchantiaceae 
a) Astroporae (Clevea, etc.) 
b) Operculatae t aceaeco' Fimbriari, etc.) 
c) Targioniae (Targionia, Cya 
d) Compositae (Marchantia, ie. etc.) 
CAMPBELL (2, p. 67) gives the following: 
Marchantieae 
a) Corsinieae 
b) Targionieae 
c) Marchantieae 
GOEBEL has proposed still another classification. In this he trans- 
poses the Riellaceae to the Marchantia group, as follows: 
a) Corsiniaceae 
b) Targioniaceae 
c) Riellaceae 
d) Marchantiaceae 
Without concerning ourselves with the relative merits of these 
schemes, it might be well to take up the one family, the Targionieae. 
This family at present contains but two genera, Targionia and 
Cyathodium, and it is with regard to the merits of placing these two 
genera within the same family that a question may be raised. In 
order the more clearly to present this question, the accompanying 
diagrams (fig. 13) have been prepared. In the key to these 
diagrams it will be seen that each generation (sporophyte and 
gametophyte) has been divided into four features, selected because 
of their bearing on a natural scheme of classification. Each of 
these divisions has been subdivided into five stages of as nearly 
equal importance as it was possible to find. 
From the diagram it will be seen that the two lines cuinside 4 in 
but two points. The one of these is D4 and the other E4, which 
represent respectively the apical position of the archegonia accom- 
panied by a checking of the growth of the thallus at this Penh and 
the common involucre. 
As for the former (D4), the character is not peculiar to this 
