As far as we can argue from the analogy of living species, the presence of large Scorpions is a certain index of the warmth of the climate in which they lived; and this indication is in perfect harmony with those afforded by the tropical aspect of the vegetables with which the Scorpion, found in the Bohemian coal-field, is associated.
SECTION IV.
Fourth Class of Articulated Animals.
FOSSIL INSECTS.[1]
Altough the numerical amount of living Insects forms so vast a majority of the inhabitants of the present land, few
traces of this large class of Articulated animals have yet
been discovered in a fossil state. This may probably result
from the circumstance, that the greatest portion of fossil
animal remains are derived from the inhabitants of salt water,
characteristic pincers on the right claw. Between this claw and the tail lies a fossil carbonized Seed, of a species common in the Coal formation. The horny covering of this Scorpion is in a most extraordinary state of preservation, being neither decomposed nor carbonized. The peculiar substance (Chitine or Elytrine) of which, like the elytra of Beetles, it is probably composed, has resisted decomposition and mineralization. It can readily be stripped off] is elastic. translucent, and horny. It consists of two layers, both retaining their texture. The uppermost of these (Pl. 46', Pig. 6. a.) is harsh, almost opaque, of a dark-brown colour, and flexible; the under skin (Pl. 46', Fig. 6. b.) is tender, yellow, less elastic, and organized like the upper. The structure of both exhibits, under the microscope, hexagonal cells, divided by strong partitions. Both are penetrated at intervals by pores, which are still open, each having a sunk areola, with a minute opening' at its centre for the orifices of the trachea. Fig 7. represents impressions of the muscular fibres connected with the movement of the legs.
- ↑ See Pl. 46″. Figs. 1. 2. & 4.—11.
