220 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



species and genera of coleoptera, neuroptera, &c. in the out- 

 lying beds in Buckinghamshire, and in the Yale of Wardour, 

 in Wiltshire. 1 



Fishes. The fossils of this class comprise but a few genera. 

 The most common belong to two species of a large ganoid fish, 

 the Lepidotus, which is closely allied to the existing Lepidosteus 

 or Bony Gar of the American rivers. The scales and teeth of 

 these fishes are very abundant ; there are some fine examples 

 of the cranium, body and fins, in Room V. Teeth and scales, 

 and the dorsal ray or spine of the genus Hybodus, belonging 

 to the shark family, are also very common. Teeth of Gyrodm, 

 Pycnodus and Sphcerodus are also met with ; and I have 

 lately collected from the strata of Tilgate Forest, remains of 

 a species of Belonostomus, a genus previously only known in 

 the chalk near Lewes. 2 



Of corals and other zoophytes I have not detected the 

 least vestige in any of the Wealden strata. Echinoderms 

 are also absent ; but Prof. E. Forbes has discovered one 

 species in the Purbeck beds. 



Flora of the Wealden. The most characteristic vegetable 

 remains are the Clathraria Lyelli, Endogenites erosa, Dracaena 

 Benstedi, Equisetum Lyelli, Lonchopteris and Sphenopteris 

 Mantelli, of which there are specimens in the Wall-cases of 

 Room I. (ante, pp. 27, 32, 45, 48). 



In a few localities (Sandown Bay and Brook Point, in the 

 Isle of Wight,) stems of coniferous trees occur in such 

 numbers, and under such conditions, as to show that the 

 accumulations are attributable to rafts of forest-trees that were 

 swept down by the flood of a great river, and deposited 

 where they are now found in a fossil state. 3 In another re- 

 markable locality, the Isle of Portland, the trees are petrified 

 on the soil, and in the position in which they grew (ante, p. 56). 



I have lately obtained numerous cones or strobiles of fir- 

 trees belonging to two distinct species, perhaps genera.* 

 Seeds of the common fresh-water plant, the Chara, have been 



1 See the Rev. J. Brodie's beautiful work on Fossil Insects. 



2 See Catalogue of the Mantellian Museum of the Royal Sussex 

 Scientific Institution. 



3 For an account of the fossil raft of coniferous trees at Brook Point, 

 see " Geological Excursions round the Isle of Wight/' p. 277. 



4 Ibid, second edition, p. 452. 



