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LETTER XVII. 
ENTOMOLITHI INSECTS IN PAPPENHEIM LIMESTONE IN COAL 
SLATE CRABS OF SHEPEY, VERONA, EAST-INDIES, AND MAES- 
TRICHT ONISCITES MONOCULITES TRILOBITES. 
The extreme softness of the parts, and the general delicacy of struc- 
ture, which exist in the smaller insects, will easily explain the circum- 
stance of their being rarely met with in a mineralized state. Very few 
indeed are the instances which I shall be able to adduce of Entomolithi, 
or of the mineralized remains of this class of animals. 
The specimen represented Plate XVII. Fig. 2, is a slab of the fissile 
cream-coloured lime-stone from Pappenheim, in which the traces of 
an insect are sufficiently plain to mark its presence, without, however, 
being sufficiently distinct, to point out the genus in which it should 
be placed. 
The head of the animal is plainly to be seen, but none of its parts 
are distinguishable. It appears to have been connected with the thorax 
by a contractile neck ; since, in another specimen, apparently of the 
same species, the neck appears to be as long as the thorax ; whilst, 
in the specimen here depicted, the distance between the head and the 
thorax is very small. The thorax appears to have been nearly cylin- 
drical, and much shorter and wider than the abdomen, which is of a 
lanceolated form, and is evidently composed of about eight articulated 
rings. In one of M. Knorr’s figures, PI. xxxiii. the tail of this animal 
VOL. III. 
M M 
