174 . CHARACTERS OF TRIBES AND GENERA. 
Veins uniform, reticulated, forming transverse elongated, 
hexagonoid areoles. Receptacles compital, elongated on the 
exterior, transverse anastomose, forming 2 linear, con- 
tinuous, marginal sorus. ; 
Type. Pteris angustifolia, Swartz. 
. Ilust. Hook. and Bauer, t. 77 A.; J. Sm., Jon Brit. 
and For., fig. 58. 
Ozs.—In general habit this genus agrees with Vitlaria 
and Anfrophywm, being distinguished from the first by its 
reticulated venation, and from Antrophyum by its strictly 
transverse marginalsorus. As now restricted, the genus 
consists of one species only ; a native of the West Indies, 
and many parts of Tropical America. 
Sp. P. angustifolia, Desv. (v v.) (Trenitis, Hook. Sp. Fil). 
- 82.—Dicryoxiruiww, Hook., (1838). 
Vernation fasciculate, erect, acaulose. Fronds simple, ` 
linear-lanceolate, attenuated and decurrent on the stipes, 
l to 3 feet long. Veins compound anastomosing, trans- 
versely combined at the margin by the sporangiferous 
 Feceptacle, which is seated in an unequal-sided extrorse e 
groove, the upper side being induseform and inflexed. 
Type. Dictyoxiphium panamense, Hook. 
Ilust. Hook. and Bauer, Gen. Fil, t. 62.; J. Sm, 
Ferns, Brit. and For., fig. 59; Hook., Syn. Fil., t. 2, 
fig. 30, b. c. ; Moore, Ind. Fil., p. 23 B. 
. Oss.—This genus is founded on a very distinct and 
peculiar Fern, a native of the district of New Granada, and 
the Isthmus of Panama on the coast of the Pacific. 
It is with some hesitation that I place this genus in 
alliance with Vittaria, from which it differs in having fas- 
ciculate erect vernation, and in the veins being compound ` 
