178 BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 
of the mature sporophytes, and designate, by the name of the 
species best representing it, each successive stage of the series. 
This will then serve as a basis for the comparison of the ontogeny 
of each species. 
MONOGRAMMA DAREICARPA Hook. (PLATE 3, FIG. I) 
The adult series begins with Monogramma dareicarpa, the 
simplest species in the whole tribe, the venation of which is a 
simple vein through the middle of the leaf. MM. graminea has the 
same type of venation but is a larger plant, so M. dareicarpa 
may better serve as a starting point. 
MONOGRAMMA SUBFALCATA Hook. (PLATE 3, FIG. 6) 
This species presents a second stage in the venation series. 
As will be shown later, it probably represents a simple dichotomy 
of the leaf trace, modified to form the areola so characteristic 
of the venation of the tribe. M. trichoidea seems to belong here, 
but its structure is somewhat in doubt. MM. paradoxa shows both 
this type and that of the third and next stage of venation. 
VITTARIA SIKKIMENSIS Kuhn (PLATE 5, FIG. 18-20) 
In V. sikkimensis, the leaf trace commonly divides twice to 
form two areolae, that is, a median vein with two lateral veins 
which anastomose anteriorly. This is in essence the venation of 
the genus Vittaria, but the latter may be better typified by a 
somewhat more advanced species. 
VITTARIA INTRAMARGINALIS Baker (PLATE 5, FIG. I) 
This same type of venation is presented in characteristic form 
by a smaller species, V. minima, but I have chosen V. intra- 
marginalis because it furnishes such a good transition to the next 
higher type. Within Vittaria the two divergent venation patterns 
might well be designated the V. remota and the V. lineata types; 
these are, respectively, the type with divergent areolae (PLATE 5, 
FIG. II; also FIG. 7 and 10), and that with longitudinal areolae 
(PLATE 5, FIG. 1). 
POLYTAENIUM QUADRISERIATUM Benedict (PLATE 7, FIG. 8) 
Polytaenium quadriseriatum resembles Vittaria intramarginalis 
€ven more closely than the venation patterns might indicate. 
