SYSTEM OF INSECTS. 4-03 



have been considered as such by preceding Entomolo- 

 gists. The four Tribes into which the two subsections 

 Geodephageua and Hydradephagena appear resolvable, 

 are not only distinguished by the characters of the per- 

 fect insect, but likewise by those of their larvae, which 

 are constructed on four distinct types ; those of the Gy- 

 ronechma being the most perfectly Chilopodimorphous 

 of the whole, and those of the Eunechiua the least so a . 

 The former appear rather to form an osculant tribe, or 

 one without the circle, than one within it ; and to be go- 

 ing off towards another section, including Hydrophilus, 

 Sphceridium, &c. I must observe, that between Dytiscus 

 and Hydrophilus there is a striking agreement both in 

 their form and habits in the larvae a , and even in seve- 

 ral characters in the perfect insect ; so as in many re- 

 spects to generate a doubt whether they ought not to 

 enter the same circle and to follow each other. Yet the 

 change of habits in the latter, which from a carnivorous 

 larva becomes a herbivorous beetle ; the consequent 

 change of structure in their oral organs, their antennae, 

 and other striking differences ; and the evident interven- 

 tion of the Gyronechma and some other osculant tribes be- 

 tween the two, forbid their union in one and the same circle, 

 vi. I need not say more on those larger groups of an 

 Order which conduct us to what are denominated its 



a VOL. III. p. 167. I formerly hinted (Tbid. p. 163.) that the 

 larva of Cicindela may be regarded as Araneidiform : this is further 

 confirmed by its having eight eyes, (and not six,} as I have since dis- 

 covered, and by the aspect of its large head and prothorax. The 

 other larvae of the Adephagana have twelve eyes. Mr. Stephens 

 (Illustrations of British Entomology. n. xv. p. 175.) has confirmed 

 the above statement, as to the number of eyes of the larva of Cicin- 

 defa. 



2 D 2 



