480 EXTERNAL ANATOMY OF INSECTS. 



ries. It is frequently, as in Tettigonia, the most conspi- 

 cuous part of the face, both for size and characters ; but 

 in the Staphylinidce it is very small, and often scarcely 

 discernible, being overshadowed by its ample front : and 

 it may be observed in general, that when the antennae 

 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 Pompilidce, Sphecidce, Vespidce, &c. of the latter. In 

 Myopa buccata, Sec. its length exceeds its width ; but more 

 commonly the reverse takes place. The circumscription of 

 the nose also deserves attention. It is usually terminated 

 behind by the front (from), or, where it exists, by the post-*- 

 nasus, in the sides by the cheeks, and anteriorly by the la~ 

 brum. But this is not invariably the case; for in the Cimi- 

 eidte, 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 

 labrum. This structure you may see in Edessa F., and 

 many other bugs. This part sometimes has its arms. 

 Thus in Copris, and many DynastidcE, the horns of the 

 head seem, in part at least, to belong to this portion of 

 it ; in Tipula oleracea (the crane-fly), &c. it terminates 

 before in a horizontal mucro. In Osmia cornuta, a kind 

 of wild-bee, each side of the nose is armed with a ver- 

 tical horn. The margin of the nose in most Lamellicorn 

 insects, though mostly level, curves upwards. 



