A Pictorial Atlas of Fossil Remains, consisting of coloured illustrations selected from Parkinson's "Organic remains of a former world," and Artis's "Antediluvian phytology."

by Gideon Algernon Mantell

Fig. 5. Trigonia excentrica; upper greensand, Blackdown. Like most of the shells from this locality, the Trigoniæ are transmuted into silex.

Fig. 6. Trigonia dædalea, Blackdown.

Fig. 7. —— spinosa, Blackdown.

Fig. 8. Enlarged view of the spines of the above.

Fig. 9. Trigonia alæformis, Blackdown.

Fig. 10. —— rudis, Blackdown.

Fig. 11. a bivalve shell of the genus Productus (P. antiquatus, of Sowerby?), from the Mountain limestone. See description of fig. 9, [Plate LXVII.]

Fig. 12. Cast of a species of Trigonia (T. clavellata), from the Portland rock. Many beds of this oolitic limestone are almost entirely made up of casts of Trigoniæ, and chiefly of this species.

Fig. 13. Trigonia sinuata, from Blackdown.

Figs. 14 to 18. "Different views of a species of Harpax."—Mr. Parkinson. (Plicatula spinosa). From the Lias, Gloucestershire.