158 BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 
are necessarily unbranched, as in Monogramma (PLATE 3, FIG. 
3, 8, 11) and Vitlaria (PLATE 2, FIG. 4, 5), but in the genera with 
pluriseriate areolation the sporangial lines frequently fork, and 
in some species anastomose again. Ananthacorus is exceptional 
with its pluriseriate venation and two simple sporangial lines, one 
along each margin. Anetium has appeared even more exceptional 
as its sporangia have always been described as occurring in round 
sori and only over the intra-areolar tissue, but, as will be described 
in connection with the genus, the sporangia are sometimes along 
the veins even in this genus. 
As noted in the tribal description, the sporangia in all but 
a few species are developed in grooves in the leaf tissue. Some- 
times the margins of these grooves are extended to meet and form 
an indusiumlike protection. This is especially well shown in 
species of Monogramma (PLATE 3, FIG. 2, 7, 9, 15, 16, 17) and 
Vittaria (PLATE 5, FIG. 6, 8,9). Usually also, there are associated 
with the sporangia, and of coordinate origin, numerous paraphyses 
which develop before the sporangia, and probably serve, as Dr. 
Copeland has suggested, to protect these in their developmental 
stages. The sporangia are superficial in about ten species, and the 
paraphyses are wanting in about the same number, but only in 
part the same species. 
The differentiated unequally thickened epidermal cells, the 
so-called “spicular” cells (PLATE 2, FIG. 7, 8), are said by Goebel 
to occur only in the Vittarieae. Copeland has recorded their 
absence in a species of Antrophyum. I have not examined the 
species carefully as to their presence, but have noted them fre- 
quently. Goebel, Mettenius, and Luerssen found them present 
in the several species they studied. 
Il. GENERA 
The species of the Vittarieae seem to fall naturally into seven 
generic groups. According to the usual taxonomic treatments 
there are only six, but one of these seems better divided into two. 
The characters upon which the genera are to be separated are 
mainly those of venation, but the arrangement of the sporangia 
is also used in the case of three genera. Of the seven genera here 
na 
