EXTERNAL ANATOMY OF INSECTS, 4.79 
in the Staphylinide it is very small, and often scarcely 
discernible, being overshadowed by its ample front ; and 
it may be observed in general, that when the antennz 
approximate the mouth, as in this genus and many others, 
the front becomes ample, and the nose is reduced to its 
minimum : but when they are distant from the mouth, the 
reverse takes place; and the nose is at its maximum and 
the front at its minimum. Mutilla, Myrmecodes, Scolia, 
&c., in the Hymenoptera, are an example of the former ; 
and the Pompilide, Sphecide, Vespide, &c. of the latter. 
In Myopa buccata, &c. its length exceeds its width; but 
more commonly the reverse takes place. The czrcum- 
scription of the nose also deserves attention. It is usually 
terminated behind by the front (frons), or, where it ex- 
ists, by the postnasus, in the sides by the cheeks, and 
anteriorly by the /abrum. But this is not invariably the 
case; for in the Geocorise, in which the cheeks form the 
bed of the Promuscis, the front embraces it on each side 
by means of two lateral processes, that sometimes meet 
or lap over each other anteriorly, which gives the nose 
the appearance of being insulated; but it really dips 
below these lobes to join the Jabrum. This structure you 
may see in Edessa, and many other bugs. ‘This part 
sometimes has its arms. ‘Thus in Copris, and many Dy- 
nastidé, the horns of the head seem, in part at least, to 
belong to this portion of it; in Z%pula oleracea (the 
crane-fly), &c. it terminates before in a horizontal mucro. 
In Osmia bicornis, a kind of wild-bee, each side of the 
nose is armed with a vertical horn. The margin of the 
nose in most Lamellicorn insects, though mostly level, 
curves upwards. 
I am next to mention a part of the nose which merits 
