14 
SYNOPSIS. 
p. 76, tab. 42, 1790. Acrostichum hyperboreum, Lilje- 
blad, Stockholm Trans, for 1793. Woodsia h. Sm. Eng. 
FI. iv. 310. Hook. Br. FI. 437. Woodsia ilvensis, var. 
Bab. Man. 384. 
Genus Allosorus, Bernhardi. Midvein distinct, lateral veins 
free: involucre not apparent: capsules near the extremity of la- 
teral veins which are often divided, epidermis bleached reflexed 
covering the capsules as in Pteris. 
1. All. crispus, fig. p. 103. Osmunda c. Linneus, Sp, PI. 1522. 
Pteris c. Sm. Eng. FI. iv. 306. Cryptogramma c. Hook. 
Br. FI. 444. Allosorus c, Bab. Man. 383. 
Genus Polypodium, Linneus, Midvein very distinct, lateral 
veins branched, branches free terminating in a small club, the 
anterior branch bearing at its extremity a large circular cluster 
of capsules which has no visible involucre. 
1. Po. vulgare, fig. p. 1 11. Linneus^ Sp. PI. 1544, and Brit. aut. 
Family. — Hymenophylle^. Filmy Ferns. 
Fronds appearing to consist of branched veins, each accompa- 
nied throughout by a membranaceous wing or margin : cluster 
of capsules nearly spherical seated on one of these veins which 
projects beyond the edge of the leaf, the cluster being enclosed 
in a kind of cup-like involucre. 
Genus Trichomanes, Linneus, Involucre elongate somewhat 
urn-shaped, capsuliferous vein projecting beyond it in the form 
of a long stiff* bristle. 
1. Tr. speciosum, fig. p. 305. Willdenow, Sp. PI. v. 514, date 
1810. Bab. Man. 390. Tr. brevisetum, Sm. Eng. FI. iv. 
311. Hook. Br. FI. 445. 
t2. Tr. Andrewsii, fig. p. 315 (as Tr. s. var. Andrewsii) : proba- 
bly a species. 
Genus Hymenophyllum, Smith. The involucre is shorter and 
rounder than in the preceding genus, the receptacle or capsu- 
liferous vein not longer than the involucre. 
1. Hy. tunbridgense, fig. p. 321. Trichomanes t. Linneus^ Sp. 
PI. 1561. Hymenophyllum t. of Brit. aut. 
t2. Hy. unilaterale, fig. p. 325 (as Hymenophyllum Wilsoni). 
