512 EXTERNAL ANATOMY OF INSECTS. 
often papillose. The antenne are generally opaque; 
but in Nebria complanata, a beetle common on the sea- 
coast in Wales and Lincolnshire, they are semi-trans- 
parent. 
The situation of antenne must next be considered. 
In this respect it seems necessary that they should be 
so situated as to be under the direction of the eyes: for 
if you examine ten thousand insects (except, as was be- 
fore observed*, where there are four eyes), you will not 
find one in which these organs are situated either above 
or immediately behind them ; their station being always 
either somewhere in the space between the eyes or that 
below them. In Ptinus they are placed near the ver- 
tex; but in Gzbbium, which is so nearly related to that 
destructive genus®, they are beneath them. In many 
Andrene they are in the middle of the space between 
the eyes; and in many other Hymenoptera and Coleo- 
ptera (Staphylinus &c.), in the anterior part of it. In 
many Lamellicorn genera, as Melolontha, Cetonia, Lu- 
canus, &c. they may be regarded as planted in the lower 
surface of the cheek before the eyes; but in Copris, &c., 
in which they are inserted further under the shield of 
the head, they are properly in the prone surface of the 
front. In the Capricorn beetles (Longicornia) and 
Amarygmus they may be termed inocular, or placed in a 
sinus of the eye; in the former tribe in its zmterior, and 
in the latter its anterior side. In the weevils (Rhynco- 
phora) they vary in their situation. Thus in Macroce- 
phalus Oliv. they are inserted at the apex of the ros- 
trum; in Anthribus in its middle, and in Calandra at its 
* See above, p. 497—. > Vor. I. p. 234, 240. 
