84 32 
towards the sinus but not meeting there and thus not being truly connivent; costulze 
run out from the coste under open angles. Sori indusiate or not, the indusium 
rarely large and persistent. Sporangia glabrous. 
Ctenitis is a very natural group, by the peculiar pubescence different from all 
other groups of the genus, and I have no doubt that the differences are of generic 
value. 'The species vary being from bipinnate to decompound, most of them with 
characteristic obtuse segments, rather small to large. All intermediates between 
bipinnate and large decompound species are found, such are f. inst D. strigilosa 
and D. Hemsleyana. In America the bipinnate species are numerous in Southern 
Brazil, while only one, D. vellea, occurs in the West Indies, where several decom- 
pound species (D. hirta, D. ampla, D. nemorosa etc.) are to be found. In the Old 
World's tropies the subgenus is fairly well represented. Among them is the African 
D. cirrhosa (Schum.) O. Ktze., which I cannot distinguish specifically from the 
Brazilian D. eriocaulis (Fée) O. Ktze., a new example of the well-known relation 
between the floras of South Brazil and tropical West Africa. 
Ctenitis is not nearly related to the other subgenera of Dryopteris and in my 
opinion it is even not congeneric with them. On the other hand it is intimately 
related to the genus Psomiocarpa Presl. recently restored by CunrsT!), who referred 
lo that genus two West Indian species, Ps. aspidioides (Griseb.) and Ps. Maxoni 
Christ. I know the first named of these species, which in habit, texture, colour 
and pubescence is perfectly agreeing with Clenitis; by its contracted fertile frond 
it differs, however, so much that it naturally must be placed in a separate genus, 
which can be regarded as a derivate of Cfenitis. Psomiocarpa was previously 
united with Polybotrya, which genus is more closely related to Polystichum. 
Ctenitis is further related to the genus Aspidium (Tectaria) at least to the 
majority of the species referred to that genus. The main difference is found in 
the venation, Ctenilis having free veins, Aspidium reticulated veins; in pubescence, 
texture and colour most species of the two genera fully agree. Species intermediate 
between the two genera exist, f. inst. Dryopteris Brauniana (Karst.) O. Ktze. from 
Colombia (KARSTEN; LiNDIiG nr. 261 (B); LEHMANN (RB)) It has free veins but is 
in habit rather a species of Aspidium, to which genus I refer it, wherefore it is 
not included in this paper. 
In the following I deal with 24 species. It is, in this subgenus, impossible 
to draw a sharp line between the bipinnatifid and the more divided species. Some 
of the species vary considerably in cutting being bipinnatifid, bipinnate or tri- 
pinnatifid. I have chosen to include in this monograph those species only of which 
I have had type-specimens and which in the most developed form are scarcely 
more than bipinnate. 
The 24 species can be divided into smaller groups, which are connected by 
intermediate characters: 
") On Psomiocarpa, a neglected genus of ferns. Smithsonian Misc. Collections 56 nr. 23. 1911. 
