Ve 
MIN AU 
WIDRKAKN 
NEW YORK 
SOTANICAL 
GARDEN 
1. Introduction. 
Al he relationship and delimitation of the genus Ahnfeltia 
have always been and are still very uncertain. The 
genus was first given a tolerably natural delimitation by 
J. G. AGARDH who distinguished it from the genus Gymno- 
gongrus near which it was placed (comp. Spee. g. o. II, 
1851, p. 310). In his Epicrisis (Sp. g. o. III, 1876, p. 205) 
this author gives the genus the same position 
and refers to it 6 species which he divides into 
three sections: Ahnfeltia, Dictyogenia and Dia- 
nema, distinguished by differences in the ana- 
tomical structure of the frond. Nemathecia 
and cystocarps are mentioned or shortly and 
incompletely described in some of these spe- 
cies, but two kinds of reproduction are never 
recorded in the same species, and it is there- 
fore doubtful whether all these species really 
belong to the same genus, even when taking 
into consideration the anatomical differences 
Fig. 1. Ahn- 
mentioned above. Scumirz in his paper on yeltia plicata. 
Actinococcus (1894, p. 396, see also Scumirz End of frond 
with nema- 
and HAUPTFLEISCH in ENGLER u. PRANTL 1896, es De. 
p. 366) took the genus in a narrower sense, cember. 
= , : . Fisted, 
comprising only J. AGARDH's section Ahnfellia, 2'/» 
while he maintained that the other two sections must be 
united with Gymnogongrus. According to SCHMITZ, not con- 
1? 
