.7 14- EXTERNAL ANATOMY OF INSECTS. 



shield of the head, they are properly in the prone surface 

 of the front. In the Capricorn-beetles (Cerambyx L.) and 

 Cnodalon F. they may be termed inocular, or placed in 

 a sinus of the eye ; in the former tribe in its interior, and 

 in the latter its anterior side. In the Rhynchophorous or 

 rostrum-bearing beetles (Curcidio L.) they vary in their 

 situation. Thus in Macrocephalus Oliv. they are inserted 

 at its apex ; in Anihribus in its middle, and in Calandra 

 at its base a . In the water-scorpions (Nejoa, Belostoma, 

 &c) they may be called extraocidar, being placed under 

 the head in its prone part, outside the eyes b . In Nir- 

 mus Fringillcc, a kind of bird-louse, they appear to be 

 oral, being situated, according to De Geer, under the 

 head near the mouth, at a great distance from the 

 eyes c . 



In their proportions, both as to length and thickness, 

 antennae vary extremely. Thus sometimes they are very 

 short — much shorter than the head; as in the aquatic 

 beetles Gyrinus, Parnus, and the water-scorpion; and 

 some land-beetles, as Anthrenus, &c. At other times they 

 far exceed the length of the insect : the males of many 

 Capricorn-beetles are so distinguished. In that of Lamia 

 ccdilis they are more than four times as long as the 

 body ; and every intermediate length between these two 

 may be found amongst them. They vary also greatly in 

 thickness : in Paussus, whose antennae emit light in the 

 night d , and Cerapterus, they are nearly as thick,— at 

 least their knob, which forms the chief part of them, — as 



a Oliv. Ins. no. SO. Macrocephalus t. i./.l— 4.; Anthribusf. 5— \2 ; 

 and no. 83. Curculio t.W. Calandra f. 16. 

 b Schellenberg Cimiccs t. xiv./. 1. b. 

 c De Geer vii. t. iv.f. 7- a a. J y f,. II. 0*421. 



