FILICES. 
383 
Suborder II. HYMENOPHYLLACE^E. 
Thecal opening irregularly; ring oblique, excentric, transverse, 
complete ; receptacle terminating a vein at the margin of the 
frond. 
Tr. VI. HYMENOPHYLLEM. The same as the Suborder. 
14. Tuichomanes. Thecae on an elongated filiform receptacle 
within a cupshaped involucre of the same texture with the 
frond. 
15. Hymenophyllum. Thecas on a narrow subclavate re- 
ceptacle within a two-valved involucre of the same texture 
with the frond. 
** Thecce without an elastic ring. 
Suborder III. OSMUNDACEJL 
Thecx without an elastic ring, regularly 2-valved. 
Tr. VII. OSMUNDEJE. Vernation circinate, rachis solid. 
Thecie stalked. 
16. Osmunda. Theca? clustered, arranged in a branched 
spike terminating the frond. 
Tr. VIII. OPHIOGLOSSE^E. Vernation straight, " rachis 
hollow." Thecae sessile. 
1/. Botrychium. Theca; distinct, disposed in a compound 
spike attached to a pinnate or bipinnate frond. 
IS. Ophioglossum. Theca? connate, disposed in a simple 
distichous spike attached to an undivided frond. 
Suborder I. Polypodiacecs. Tribe I. Polypodies. 
1. Allosorus Bernh. 
1. A. crispus (Bernh.) ; barren fronds bipinnate: pinnae 
wedgeshaped or linear-oblong often bifid at the end, pinna? of the 
fertile fronds oblong. — Newrn. Ferns, p. 17. Pteris Sm. E. B. 
1160. Cryptogramma R. Br., Hook. — Fertile frond nearly trian- 
gular. Veins alternate, mostly forked and each branch termi- 
nating in a sorus which is totally without an indusium but con- 
cealed by the involute margins of the pinnule. Height 6 — 12 in. 
St. slender, very brittle. — Stony places on mountains, occasion- 
ally on old walls. P. VII. Rock Brakes. 
2. Polypodium Linn. 
1. P. vulgare (L.) ; fronds deeply pinnatifid : lobes linear- 
