KIDSTON : YORKSHIRE CARBONIFEROUS FLORA. 117 
Sphenophyllum tenerrimum Achepohl (not Ett.) Niederr. 
Westfal. Steink., p: 136, pl. xli.; fig. 12% Suppt: pl. iv., 
fig. 76. 
Additional localities. 
MIDDLE CoaL MEASURES. 
Hor.—Barnsley Thick Coal. Loc.—Hemsworth Colliery, 
near Pontefract. 
Hor.—Stanley Main Coal. Loc.—Walton, near Wakefield. 
CORDAITEE. 
CORDAITES UNGER. 
The Cordaites have been divided into four groups :— 
I.—CORDAITES (or EUCORDAITES). 
II.—DORYCORDAITES. 
III. —POACORDAITES. 
IV.—SCUTOCORDAITES. 
The first three divisions were proposed by Grand'Eury, 
(Flore Carbon. du Départ. dela Loire, etc., pp. 208, 214, 222, 
1877), and the last was founded by Renault and Zeiller (Comptes 
Rendus, 23 Maich, 1885; see also Flore foss. terr. houil. de 
Comentry, p. 603, 1890). Of these, only the two first groups 
have been found in Yorkshire, which are distinguished as 
| follows :— 
1.—Cordaites. Leaves simple, sessile, entire, lanceolate, 
rounded at the summit, spathulate, obovate or elliptical, 
generally very large, twenty to ninety centimetres long, 
coriaceous, veins parallel, fine, equal or unequal, and 
| running throughout the whole length of the leaf. 
II.—Dorycordaites. Leaves simple, sessile, entire, lanceolate, 
slender, forty to fifty centimetres long, veins equal, 
numerous and distinct, and running throughout the whole 
length of the leaf; apex of leaf always terminating in a 
point (not rounded as in Group 1.). 
