EXPLANATION OF THE PLATES. 85 
Fic. 4.—a, b. (?) LEPIDODENDRON NoTHUM, Unger. 
Salter, Quart. Jour. Geol. Soc., vol. xiv., p. 75, pl. v., fig. 9, a, 6. Siluria, 
4th ed., p. 269. Foss., 73, fig. 4, 4a. 
a, b. Original. a. Branching stem. 6. Group of scales, or bracts, from 
surface of 4a. Enlarged. Wick, Caithness. 
Mippite Orp Rep SanpsTonE.—Caithness flags, Siluria, 4th ed. Table 
of Upper Paleozoic rocks, p, 406. 
