Lign. 182. Insectiferous Limestone. Purbeck.
(Magnified six diameters.)
| a, b. | Membranous wings of the Corydalis type. |
| c. | Punctate-striate elytron of a Beetle. |
| d. | Elytron of a Beetle, with a smooth surface. |
| e. | Smooth elytron, the upper part impressed with transverse lines. |
The Orthoptera, Homoptera, and Diptera are also represented in the Lias of Gloucestershire, and in the Purbeck strata of the Vale of Wardour, by numerous species, which have been enumerated, and mostly discovered, by the Rev. Mr. Brodie.[499] This observer has, indeed, been very successful in his researches in the latter locality, for in the deposits of limestone and marl which yielded the isopodous crustaceans, previously described ([p. 521], [Lign. 171]), he has discovered the remains of several orders of insects, and states that, for abundance and variety of specimens, the beds may be said to resemble the Tertiary marls of Aix and Œningen. These remains were obtained from a quarry at Dinton, about twelve miles west of Salisbury. They consist chiefly of Coleoptera, with the remains of Neuroptera, Trichoptera, and Homoptera, and of several species of Diptera. In the cream-coloured laminated Purbeck marls that axe exposed in Durlstone Bay (about one mile from Swanage) insectiferous beds have been found by the Rev. O. Fisher and Prof. E. Forbes, which are the equivalents of those of the Vale of Wardour; and similar beds were met with in the cutting of the railway through the Ridgway Hill, between Dorchester and Weymouth.
[499] See Brodie’s Fossil Insects.
In a quarry on the road-side between the village of Stone and Hartwell, Bucks, the Portland Oolite is covered by the Purbeck marls; in these latter remains of Insects occur, together with scales and teeth of small Fishes, and abundance of Cyprides.
All the British localities of fossil insects have now been alluded to; but on the Continent, independently of the celebrated limestones of Solenhofen, to which reference has been made, [p. 550], there are several tertiary deposits exceedingly rich in these interesting fossils.
FOSSIL INSECTS.
Fossil Insects of Aix, in Provence.—The town of Aix is situated in the lowest part of a deep valley, the immediate flanks of which are composed of a thick fresh-water formation, lying unconformably upon strata of Jura limestone. The fresh-water series consists of white and grey calcareous marls, calcareo-siliceous grits, and beds of gypsum; and the quarries formed in the latter rock have long been celebrated for the prodigious quantity of fish and plants which they contain. M. Marcel de Serres first made known the great abundance of insects in these gypseous marls, and has enumerated nearly seventy genera, chiefly of the Coleoptera, Diptera, and Hemiptera; they are mostly referable to European forms, and to existing genera. An interesting Memoir on these strata, by Sir R. Murchison and Sir C. Lyell,[500] first directed the attention of the English reader to these beautiful fossils. In Wond. p. 261, an epitome of this valuable communication is given, and five specimens of insects are here figured, which will convey some idea of their forms and perfect state of preservation.
[500] Edinburgh New Philosophical Journal for October, 1829.