155 



tilaginous-edged ; venation translucent, areolae very fine, oblong, di-- 

 rected to the margin ; fertile fronds, quite erect, much taller, on stouter 

 more fleshy and longer stipites ; corpuscles pruinose, darker with age, 

 sausage-shaped, pale and translucent. Chrysodiurn Jenm, in Timehri, 

 vol. lY, part 2, A. aureum, Linn. Eat. Fer. N. Am. p. 58., Bermudas. 



A much larger species than the last, of shuttlecock habit the sterile 

 fronds shorter, spreading on the exterior, the fertile taller, and erect 

 in the centre. It is marked by numerous distinguishing characters 

 from the last with which it has been long confounded, the more ob- 

 trusively obvious of which are — its much larger size, numerous crowd- 

 ed fronds, the barren and fertile being uniformly separate — all the pin- 

 nae of the one being barren and all of the other fertile, — much more 

 numerous sessile leaflets (turned transversely with the rachis, the plane 

 to the sky like the blades of a step-ladder) intestiniform translucent 

 pale — colouredcorpusclescovering the sporangia, which give a pale prui- 

 nose colour to the soriferous under surfaces. As indicated above, this 

 is the plant figured in Eat. Fern. N. Am. for A. aureum, though true 

 aureum is also found in Florida. It ranges from Florida and the Ba- 

 hamas down through the West Indies and Guianas to the Brasils. 



Tribe XY. Ceratopteride^. 



Sori linear or interrupted, on the longitudinal veins, diffuse ; sporan- 

 gia sessile, rather large globose, very fragile, having broad rudimentary 

 or more or less extended or complete striated vertical ring, splitting 

 at length crosswise ; spores rather large granular. 



This is a singular division, of very doubtful affinity, represented by 

 a single anomalous species. I follow Eaton in placing it after Gleichen- 

 iacece. It is marked from any other by the globose sessile capsules 

 having to some, much varying, extent a broad vertical band. 



Genus XXXYII. Ceratopteris, Brong. 



Sori linear, in one to two rather irregular rows ; receptacles formed 

 of the longitudinal distantly connected veins, upon which the sporangia 

 are laxly arranged or scattered, and covered by the membranous re- 

 flexed conniving indusseform margins ; fronds herbaceous, barren and 

 fertile difPorm. 



The linear sori covered by the membranous margin which forms an 

 adventitious involucre, might seem to suggest to ally this genus with 

 PteridecBy from which however the character of the sporangia distinctly 

 and widely removes it. The only representative is a widely spread and 

 variable acaulescent aquatic plant. 



1. C thalictroides, Brong. — Stipites several, springing from central 

 scaly buds, which by adhesion form the short herbaceous rootstock, rib- 

 bed, with rather large longitudinal air vessels ; fronds herbaceous, light 

 grass green, of two kinds ; the barren 3-6 in. each way, roundly lobed 

 or pinnatifid, viviparous in the axils, the veins freely reticulated, the 

 stipites short; fertile 6-18 in. each way, on stipites 6-10 in. 1. decom- 

 pound, tri-quadri-pinnatifid ; ultimate segments linear, convolute but 

 flattened, divaricating, a line or less wide, and 1-2 or 3 in. 1. the mar- 

 gins conniving beneath over the sori ; veins in narrow longitudinal 

 areolae. — Eat. Fer. N. Am. pi. 80. Parkeria pteroides, Hk., Hk. & Gcr 

 Fil. t. 97. 



