134 Fossil Plants of the genus Sigillaria. 
EXPLANATION OF THE PLATES. 
PLATE I., VOL. 36, p. 21. 
Fig. 1. Diagram representing a transverse section of Sigillaria elegans, copied 
from Brongniart; a, a, a, the bark ; b, the ligneous cylinder; ¢c, the medullary 
sheath ; c, bundles of tissue supposed to pass from the medullary sheath into the 
leaves ; d, the pith. 
Fig. 2. Outline of the surface of a portion of the stem of one of the North 
Biddick Sigillarias, preserved in the Newcastle Museum; a, the ribs; 6, the 
furrows. 
Figs. 3, 4, and 5, represent the mode in which five different appearances may 
be produced by one specimen of Siyiilaria. 
Fig. 6. Portion of a rib of Sigillwria, shewing the leaf scar a, the vascular 
sears 6, and the remains of the axillary bud c. 
PLATE IV., VOL. 36, p. 290. 
Fig. 1. Cuticle of the larch, representing the ribbed appearance produced by 
the elongation and the arrangement of the leaf bases a. 
Figs. 2, 3, (PLATE Y,). and 4, exhibit the direction of the spiral in different 
specimens of Lepidodendron. 
Fig. 2 a. Lozenge of Lepidodendron, shewing the axillary bud a. 
Fig. 5. Portion of the cuticle of Abies Webbiana, which shews the way in 
which the ribs of Sigillaria have been produced. J am indebted to Mr Thorn- 
hill, the Librarian of the Literary and Philosophical Society of Newcastle, for 
the beautifully correct drawings from which this and the adjoining figure were 
copied, besides several suggestions in Botany, which have been of considerable 
advantage to me in drawing up these “ Contributions.” 
Pate V, VOL. 36, p. 290. 
Fig. 6. Portion of a Sigillaria shewing the direction of the spiral, and the 
way in which the ribs have been produced. 
Fig. 7. Veining of the leaflets of Otopteris pectiniformis. 
Fig. 8. Veining of the leaflets of Palwozamia pecten. 
Fig. 9. Veining of the leaflets of Pecopteris nervosa ? 
Puate IV., Vou. 38. 
Fig. 1. Transverse section of the vascular cylinder and the ligneous zone of 
Anabathra pulcherrima, divested of the bark, as seen by a low magnifier ; a, lig- 
neous zone; b, vascular cylinder; ¢, part occupied by the pith ; 7, leaf cords. 
Fig. 2. Transverse «ection of the same parts very much magnified ; a, tissue of 
the ligneous zone ; , tissue of the vascular cylinder ; ¢, space occupied by the 
pith; d, medullary rays; /, leaf cords. 
former is Sigillaria : the No. 3 specimen is evidently in this predicament ; it is 
the case with the one found in Kenilworth pit, and it appears to be the same with 
one of the Dixonfold fossils. 
