STATES OF INSECTS. (Larva.) 117 
variable head. Those of the remaining orders, with 
the exception, perhaps, of some Hymenoptera and Lepi- 
doptera, are furnished with these organs ; and in the 
Coleoptera, all the predaceous tribes, as well as most of 
those that are herbivorous or granivorous, and the Gnats 
and other Tipularie in the Diptera, are also distin- 
guished by them. In the larvee of the dragon-flies 
(Libellulina), and the Neuroptera, they are composed 
of many facets as in those of the perfect insect, from 
which they differ chiefly in being smaller. But in the 
other insects of this description they are simple, and re- 
semble those of the Arachnida, and many Aptera. These 
simple eyes vary in their number, in different genera 
and tribes, from one to six on each side of the head. 
Thus the larva of Telephorus, and the saw-flies, has only 
one»; those of the tortoise-beetles (Casstda) have three‘; 
that of Cicindela four, the two posterior ones being large 
with a red pupil surrounded by a paler iris, which adds 
to the fierce aspect of this animal; and the anterior ones 
very minute; of Staphylinus, also four ; of Timarcha 
(the bloody-nosed beetle) five ; of Carabus and the Lepido- 
ptera in general, six. In the last they are of different 
sizes, and generally arranged in a circle: in that of Heme- 
robius there are five in a circle, with one central one‘. 
The appearance of these globules, which are often not 
visible but under a powerful lens, is so different from 
@ Mr. W.S. MacLeay (Philos. Mag. N. Ser. N. 9. 178) says that 
the head of Diptera, when fully exerted, is not of a variable, but of 
a constant form. 
> De Geer iv. 66. ii. 922. © Ibid. v. 170. 
¢ De Geer says, he could not make out the number of eyes of the 
larva of the whirlwig (Gyrixus): probably, as in that of Dytiscus, 
there are six. iy. 362. 385. 
