BENEDICT : ANTROPHYUM 451 
and narrow, axes longitudinal, cross-veinlets transvese ; venation 
indistinct. 
West Indies and Mexico, south to Bolivia. Altitude: 500— 
1000 meters. 
This is the most widely distributed of all the American species 
of Antrophyum. It is easily distinguished from A. lanceolatum, 
with which it is often associated, by its long straight soral grooves. 
In the broadest fronds, besides the longitudinal grooves, a series 
of short divergent ones may occur along each margin. One frond 
was seen which was intermediate between A. /anceolatum and A. 
* Zineatum in soriation and general appearance. 
It is frequently referred to as a close relative of Vittaria, but it 
is really no more closely related than other species of Antrophyum. 
The only point of similarity is found in the deep soral grooves, 
which are, however, of little importance in determining the rela- 
tionship as compared with the venation. In Vi¢taria this consists 
of a costa and two submarginal veins formed by the interlocking of 
pinnate branches from the axial vein. In Antrophyum, the vena- 
tion consists of a primary costa, and a secondary system of reticu- 
lated veins of uniform size. In the narrow species of Vittaria, the 
pinnate veins are almost indistinguishable, and the venation appar- 
ently consists of three primary veins. Antrophyum lineatum seems 
to be in the process of developing a system of several longitudinal 
veins connected by secondary cross-veinlets, apparently in a man- 
ner similar to that in which the narrow species of Vittaria have 
evolved from the broader forms, but related to Vittaria only 
through some ancestral form of both. The process seems to take 
place by the gradual suppression of the transverse veins, first by 
a loss of fertility followed by a diminution in size. .A. lanceolatum 
represents an earlier stage of the same process. In it the soral 
lines are mainly on the longitudinal veins, but not to such an ex- 
tent as in the related species. If they were immersed the resem- 
blance would appear much stronger. 
3- ANTROPHYUM LANCEOLATUM (L.) Kaulf. Enum. Fil. 198. 1824. 
Hemionitis lanceolata L. Sp. Pl. 1077. 1753. (Type from Jamaica.) 
Dictyogramme lanceolata Trev. Atti Ist.Ven. V. 3: 592. 1877. 
Antrophyum Féei Schaffner ; Fée, Mém. Foug, 7: 42. pl. 22:7, 2. 
1857. (Type from Mexico.) 
