Part 20

---- on the Structure of the Woody Zone of an Undescribed Form of Calamite, Mem. Lit. Phil. Soc. Manchester, vols. iv. and viii. 3d series.

---- on Volkmannia Dawsoni, ibid. 1870-71.

---- on Zamia gigas (Williamsonia gigas), Linn. Trans., xxvi. 663.

---- on the Organisation of Fossil Plants of the Coal Measures, Part I., Calamites, Phil. Trans. R.S.L., vol. 161, p. 477.

Witham, on the Structure of Fossil Vegetables.

Yates, on Zamia gigas, Proceed. Yorkshire Phil. Soc., April 1847.

Young, J., and Armstrong, Jas., on the Carboniferous Fossils of the West of Scotland, Trans. Geol. Soc. Glas., vol. iii.

Besides geological treatises such as those of Ansted, Beudant, Jukes, Lyell, and others.

EXPLANATION OF PLATES.

PLATE I.

Fig. 1. Palæopteris Hibernica, Schimper (Cyclopteris Hibernica, Forbes). One-sixth the natural size.

Fig. 2. A pinnule somewhat magnified, showing the venation.

Fig. 3. A fertile pinna, natural size.

Fig. 4. Two cup-shaped indusia borne on the rachis.

Fig. 5. Sporangia enclosing spores. From the Coal-measures.

Fig. 6. Sporangia of Hymenophyllum Tunbridgense, Sm. (Fern of present epoch.)

Fig. 7. Sporangium of Polypodium vulgare, Linn. (Fern of present epoch.) Figs. 5, 6, and 7, magnified to the same extent.

Fig. 8. Transverse section of Osmundites Dowkeri, Carruthers.

Fig. 9. Two cells of Osmundites, filled, the one with starch granules, and the other with mycelium of a fungus.

PLATE II.

Fig. 1. Cycadeostrobus ovatus, Carr. From the Wealden, Isle of Wight.

Fig. 2. Beania gracilis, Carr. From the Yorkshire Oolite.

Fig. 3. Bennettites Saxbyanus, Carr. From the Lower Greensand of the Isle of Wight.

Fig. 4. Pinites Leckenbyi, Carr. From the Lower Greensand of the Isle of Wight.

Fig. 5. Trigonocarpon olivæforme, Lindl. and Hutt. From the Coal-measures, Manchester.

Fig. 6. Trigonocarpon sulcatum, Carr. Coal-measures, Wardie, Edinburgh.

Fig. 7. Sequoiites Gardneri, Carr. From the Gault at Folkestone.

Figs. 8, 9. Cupressinites Thujoides, Bowerbank. From the Eocene at Sheppey.