Lign. 28. Lonchopteris Mantelli.
Wealden, Tilgate Forest.
| Fig. | 1. & 2.— | Leaflets magnified, to show the reticulated venation. |
| 3.— | A fragment of a frond; nat. |
FOSSIL FERNS. LONCHOPTERIS.
Lonchopteris (spear-leafed.) [Lign. 28.]—Leaves many times pinnated; leaflets more or less adherent to each other at their base, traversed by a midrib; secondary veins reticulated.
The three known species which compose this genus resemble the living ferns of the genera Lonchitis, Woodwardia, &c. Two have been found in the coal-measures, and one species in the Wealden formation of England and Germany (Foss. Tilg. For. pl. iii.) This last appears to have been a delicate plant; for though fragments are very common in the micaceous grits and clays, any considerable portion of a leaf is of rare occurrence. M. Graves found the same fern near Beauvais in France, in strata, which, from the presence of the fresh-water limestone called Sussex marble, are supposed to be referable to the Wealden epoch. This Lonchopteris is widely spread through the Wealden; and occurs also in the Greensand. Mr. Morris first observed it in the iron-sandstone of Shanklin Chine.[86]
[86] Geol. I. of W. 2d Ed. p. 230.
