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. 6. A silicified branched sponge, (Spongites lobatus, of Dr. Fleming,) from the chalk of Berkshire.

Fig. 9, is a beautiful silicified, lobate, spongoid body, (Siphonia,) probably from the greensand. Siliceous cruciform spicula obtained from this fossil are represented in fig. 8.

Zoophytes of this kind, like many of the sponges, have their tissues strengthened by, and largely composed of spicula, which vary in form and size in the different species and genera. Many sponges and Siphoniæ in flint, and in the chert of the greensand, consist almost entirely of spicula, which may be easily detected by a slightly magnifying power.

Fig. 10. Another common Dudley Coral. (Porites pyriformis, of Mr. Lonsdale.)

Fig. 11. A beautiful coral (Explanaria flexuosa, of Dr. Fleming), from the Coral Rag of Steeple Ashton, Wilts. The outline indicates the mode of increase, according to Mr. Parkinson, of this form of zoophyte.

Fig. 12. This is a portion of a delicate ramose sponge (Spongites ramosus, of Mantell), whose remains are abundant in the chalk-flints, and have given rise to the irregularly branched siliceous nodules. A specimen nine inches long, with seven branches, is figured in Fossils of the South Downs, Pl. XV. fig. 11. Siliceous spicula are thickly interspersed throughout the mass.

Plate XL.