516 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 41. 



Fig. 6. — Similar bract strongly concavo-convex, partially clasping tlie axis, and 

 showing a nervation apparently in agreement with that of the Gigantopteris sterile 

 frond. 



(Cat. No. 34067, U.S.N.M. Figure, natural size.) 



Plate 49. 

 Gigantopteris americana. 



Fig. 1. — Fruit from which the thin outer envelope (wing, or lamina) has been par- 

 tially broken away, exposing the flattened nutlet, which has a thin sclerotic test. 



(Cat. No. 34081, U.S.N.M. Photographed in natural size.) 



Fig. 2. — Seed attached to axis. The photograph shows the asymmetrical form of the 

 fruit, the narrow keeled rib at the lower border, and the nervation radiating from the 

 point of attachment. The small roundish body in the upper part of the nucellus may 

 be interi^reted as a megaspore. The lamina wing is puckered about the micropylar 

 region. 



(Cat. No, 34082, U.S.N.M. Figure, natural size.) 



Fig. 3. — Seed covered by the wing lamina in which the nervation, apparently in 

 accord with that of Gigantopteris, is indistinctly seen. The nutlet is slightly apiculate. 



(Cat. No. 34083, U.S.N.M. Photograph, natural size.) 



Fig. 4. — Seed in which the outline of the nutlet is indistinctly seen beneath the 

 wing lamina, which, as in the other specimens, is narrowly ribbed on one side (left), 

 radiately nerved, and puckered about the micropylar region. 



(Cat. No. 340G4, U.S.N.M. Figure, natural size.) 



Fig. 5. — Seed in which the nervation of the wing lamina, radiating from the point 

 of attachment, and the lateral rib are more distinctly shown. 



(Cat. No. 34079, U.S.N.M. Illustrated, natural size.) 



Fig. 6. — Seed dimly outlined beneath the wing lamina. The broken lateral rib 

 is shown on the right, and the nervation is indistinctly seen along the upper border of 

 the wing. 



(Cat. No. 34068, U.S.N.M. Figure, natural size.) 



Fig. 7.— Detached fertile scales of the type shown in figures 3 and 4 on plate 49. 

 The photograph shows the upper or convex surface tlurough which the impressions of 

 the supposed pollen sacs lying underneath the scales are brought into relief. The 

 border zone of these specimens is the same as that shown in figure 5, plate 48, and 

 figures 3 and 4 on plate 47. 



(Cat. No. 34076, U.S.N.M. Illustrated, natural size.) 



