STATES OF INSECTS, 117 



amongst the Coleoptera, are without them, and probably 

 several others ; and amongst the Diptera, all those with 

 a membranous or variable head. Those of the remain- 

 ing orders, with the exception, perhaps, of some Hymen- 

 optera and Lepidoptera, 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 Tipulidans ( Tipularice Latr.) in 

 the Diptera, are also distinguished by them. In the lar- 

 vae of the dragon-flies (Libellula L.), and other Neuro- 

 ptera, 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 resemble 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 a ; that of Cicindela three, 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 one very minute. Those 

 of the tortoise-beetles also (Cassida) have three b ; of 

 Staphylinus, four ; of Timarcha (the bloody-nosed beetle) 

 Jive; of Carabus, and the Lepidoptera in general, six. 

 In the last they are of different sizes, and generally ar- 

 ranged in a circle: in that of Hemerobius, there are five in 

 a circle, with one central one c . The appearance of these 



a De Geer iv. 68. ii. 922. 



b De Geer v. 170. 



c De Geer says, he could not make out the number of eyes of the 

 larva of the whirlwig (Gyrinus) : probably, as in that of Dyliscus, 

 there are six, iv. 382. 385. 



