176 BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 
A small but marked difference in the venation emphasizes fur- 
ther the distinction between the two groups. In Euantrophyum 
the marginal veinlets are rarely if ever free, but rather as indicated 
in FIG. 2, PLATE 6. In Antrophyopsis the outermost veinlets are 
free quite to the margin, and the latter is always more or less 
thickened. It should be stated, however, that although Antro- 
phyopsis is confined to African regions, Euantrophyum is also 
represented there by one species, A. immersum Hook., outside of 
the usual subgeneric range in Oceanica and Malaysia. 
Further reference will be made to Antrophyum in connection 
with the ontogenetic studies. 
Ill. ONTOGENETIC STAGES OF VITTARIEAE 
I have endeavored to show in connection with a study of the 
mature sporophytes of the various vittarioid genera that these 
form together a complete series of connected venation types, be- 
ginning with Monogramma at the lower end of the series, and 
ending doubly, on the one hand with Polytaenium, Anetium, and 
Ananthacorus, and on the other hand with Antrophyum. The 
Polytaenium type is connected with WM, onogramma through Vittaria. 
The Antrophyum type, it was noted, may, according to resem- 
blances afforded by various mature species, be derived directly from 
the Hecistopteris type without the intervention of vittarioid or 
twin net types. If I have presented the facts clearly, it has been 
made apparent that the tribe offers a completely connected series 
of venation patterns ranging from the uninervate Monogramma 
type to the well-developed areolate system in Polytaenium and 
the others. 
This series is even more clearly demonstrated in the ontogenetic 
stages of certain species of the more advanced genera, and I 
wish now to point out in detail just how exactly the ontogenetic 
series agrees with the series shown by the mature plants. 
I have been able to obtain young sporophytes of five species, 
viz., Vittaria remota, V. intramarginalis, Polytaenium lanceolatum, 
Ananthacorus angustifolius, and Antrophyum reticulatum. The 
Viltaria remota material was obtained from plants grown at the 
New York Botanical Garden from spores brought from Jamaica, 
