CHARACTERS OF TRIBES AND GENERA. 203 
ceratum, Mett. (v ei: A. apiifolium, Schk. (v v.); A. 
coadunatum, Wall.* (v v.). 
105.—Crctopium, Presl. (1836). 
Aspidium, sp., auct. ; Hook. Sp. Fil. 
Vernation sub-sarmentose, hypogeous. Fronds pinnate, 
2 to 3 feet high; sterile pinne broad elliptical, linear- 
lanceolate. Veins pinnately forked; venules acutely 
anastomosing, producing from their angular junctions an 
excurrent free or anastomosing veinlet ; fertile pinne con- 
tracted, linear lanceolate. Veins uniform, reticulated. 
Receptacles medial, punctiform. Sori round, confluent, and 
occupying the whole under surface, Indusium obicular. 
Type. Aspidium confertum, Kaulf. 
Illust. Hook. and Grev., t. 121; Hook. and Bauer, t. 
49, B.; Moore Ind., p. 67, A.; J. Sm. Ferns, Brit. 
and For., fig. 67. 
Oss.—In many points of structure this genus agrees 
with Cyrtomium, the chief difference being the hypogeous 
sub-sarmentose vernation, the more simply anastomosed 
venation, and the specially contracted fertile fronds. The 
latter character also is the chief distinction between this 
genus and some species of Nephrodiwm, in which the 
fertile fronds have a tendency to contraction. I restrict 
Cyclodiwm to three described species, natives of Eastern 
Tropical America. In the “ Species Filicum " Hooker unites 
Aspidium confertum of Kaulfuss with A. meniscioides, Will- 
denow, but judging from cultivated specimens of A. 
confertum of British Guiana, as compared with herbarium 
specimens of A. meniscioides from Trinidad, they appear to 
me to represent distinct species. 
* Phlebigonium, Fée, is probably only a starved imperfect specimen 
. of this species. 
