213 
anatomy of the mole- cricket. 
capable of freely transmitting light ; all the remaining por- 
tion is covered, on the interior surface, by an opaque pulpy 
membrane, or pigments of a mulberry colour ; yet the por- 
tion obstructed by this pigment is in itself nearly as trans- 
parent as flint-glass : it is studded over on the interior sur- 
face with numerous depressions of a circular form, which, 
being very closely set together, give it a reticulated appear- 
ance. 
The stemmata are placed between the middle of the com- 
pound eyes, so as to be rather further from each other than 
from the eye of the same side. They are not so large as a 
very minute pin’s head, of a lenticular form, perfectly trans- 
parent, but not quite colourless, resembling particles of very 
pale cairngorum quartz. In two instances I have found only 
one of the stemmata, without any trace of the other. An 
anomaly somewhat of the same kind has been observed by 
the father of my friend Dr. Ogle, of this University, in the 
case of a man ; on one side of whose breast the usual rudi- 
ments of a mamma were entirely wanting. 
With respect to the small quantity of light admissible 
through the cornese of the eyes of the mole-cricket, it is ap- 
parently sufficient for the purposes of an animal living 
almost constantly underground. The spherical form of that 
part of the corner which is itself incapable of transmitting 
light is probably intended, as was suggested to me by Mr. 
Whessel, to whom I am indebted for the principal drawing 
which accompanies this paper, as a protection for the vertical 
transparent portion. 
The thorax.^ The form of this part is that of an irregular 
* Vide fig. 3 and 4. 
