emm 
` 
` 
b 
\ 
312 CHARACTERS OF TRIBES AND GENERA, 
fronds contracted, bipinnate, segments baccæform, compactly 
filled with sporangia, which rise from four to six puncti- 
form receptacles, each furnished with a lateral, cucullate, 
membraneous indusium. 
Type. Onoclea sensibilis, Linn. 
Illust. Hook. and Bauer, Gen. Fil., t. 82; Moore, Ind. — 
Fil., p. 65 A. ; J. Sm., Ferns, Brit, and For., fig. 106; —— 
Hook., Syn. Fil., t. 1, fig. 9. 
Oss.—This genus, as here restricted, consists of a solitary 
species of peeuliar habit and somewhat doubtful relation- 
ship. In my Arrangement of 1841, and previously (1838), 
in a note at tab. 82 of Hooker and Bauer's “Genera 
Filicum,” I stated that the membraneous scales found inter- 
posed between the confluent sori were truly special laterally 
attached indusia, and I therefore placed it in proximity 
with Aspidiwm, thus removing it from the vicinity of Blech- 
num and Woodwardia, where it originally stood, but later 
and more careful examination of the natural affinities of 
Ferns, has led me to place it again in the tribe Blechnec, 
its nearest ally being the genus Lorinseria. 
In the “Species Filicum" the genus Struthiopteris is 
united with Onoclea, but it is quite at variance with Onoclea ` 
technically as well as in habit. 
Sp. O. sensibilis, Linn. (v v.) 
A native of North America. 
179.—SrENoCHLENA, J. Sm. (1841). 
Aerostichum auct., Hook. Sp. Fil. 
. Vernation uniserial, distant, sarmentum elongated, scan- - 
dent. Fronds 2 to 3 feet long, of two forms, the sterile — 
pinnate, the fertile contracted, pinnate or bipinnate ; pinnæ 
articulated with the rachis, Veins rising from an obscure 
