408 EYES AND SKIN PRESERVED. 
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. 
back (PI. 46', Fig. 1.) has been obtained by cutting into tlie stone 
from behind. 
The under surface of the animal is well exposed in Fig. 2, with 
its 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 Ely trine) of which, like the 
elytra of Beetles, it is probably composed, has resisted decompo- 
sition 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 (PI. 46, Fig. 6. a.) is 
harsh, almost opaque, of a dark-brown colour, and flexible ; the 
under skin (PI. 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. 
