THE FOSSIL OSMUNDACEuE. 215 



In addition to a few structural features added by Eichwald, the leaves are said to 

 be very close. 



Sphallopteris, Corda (emend.). 



1845. Sphalmopteris, Corda, Flora der Vorwelt, p. 76. 



Stem arborescent, round, external cushions elevated, spirally arranged (5/8). 

 Cicatrices showing the impression of a centred depressed simple horse-shoe shaped 

 vascular bundle. 



The type of Corda's Sphallopteris is the stem which Brongniart referred to his 

 Anomopteris Mougeotii* and which is figured in the Hist. d. veget. foss , vol. i., pi. lxxx.f 



Brongniart believed this fern stem to have borne the fronds he named Anomopteris 

 Mougeotii, | on account of their large size and being found in the same bed as the stem. 

 They were not, however, found in organic union, hence the uncertainty of the stem and 

 fronds belonging to the same species ; and this consideration induced Corda to place the 

 stem in a separate genus. 



It is very interesting to notice that traces of a semilunar vascular bundle were seen 

 on some of the broken-over petioles, which are compared to those of Osmunda regalis 

 by Brongniart. 



Eichwald thus describes the genus : — 



Sphallopteris (Corda), Eichwald (emend.). 

 1860. Sphallopteris, Eichwald, Lethsea Rossica, vol. i., p. 92. 



The exterior of the stem is composed of a cortex form,ed of adventitious rootlets 

 and petiole bases or cushions disposed in regular spiral series, and which are very 

 prominent and very large, and show in transverse section cicatrices in the form of a 

 horse-shoe in the middle or on their surfaces. 



" The cushions are triangular or almost rhomboidal, the two lateral edges are always 

 acute, the inferior or anterior margin is also acute, but the superior or posterior margin 

 is rounded, rarely pointed, and is not raised up above the surface of the stem, as the 

 inferior ; it loses itself likewise in the leaf ; the horse-shoe shaped vascular bundle has 

 its two extremities bent in as a hook. 



" The interpulvinar area is entirely riddled with vascular bundles, which form some- 

 times vertical rows, or which are sometimes disposed horizontally, leaving large furrows 

 as the traces of their former existence. 



" The woody body (cylindrus ligneus) is small, narrow, and occupies the axis of the 

 stem ; the vascular bundles which compose it diverge in all directions and ascend 

 obliquely" (the leaf-traces). 



* " Essai d'une Flore d\\ gres bigarre," Ann, d. Sc. Nat, Dec. 1828, p. 4. 



t P. 261, 1831 or 1832. 



| Loc. cit., pis. lxxix. and lxxxi. 



