EXTERNAL ANATOMY OF INSECTS. 555 



nels ; in the genus last mentioned, however, the dorso- 

 lum is distinct, subrhomboidal, and received by an angu- 

 lar sinus of the scutellum, which last, I think, is not the 

 part that has usually been regarded as entitled to that 

 denomination ; for this opinion I shall soon assign my 

 reasons. 



3. Scutellum*. Some writers on the anatomy of in- 

 sects, looking, it should seem, only at the Coleoptera and 

 Orthoptera, have regarded the dor solum and scutellum as 

 forming only one piece b , and others have affirmed that 

 the Lepidoptera and subsequent Orders have no scutel- 

 lum . But as we proceed in considering the scutellum 

 in all the Orders, we shall see that both these opinions 

 are founded on partial views of the subject, and that all 

 winged insects have a scutellum, more or less distinctly 

 marked out or separated from the dorsolum. In the Co- 

 leoptera the scutellum is usually the visible, mostly trian- 

 gular, piece that intervenes between the elytra at their 

 base d , and which terminates the dorsolum. Some Lam el - 

 licorn beetles, &c. {Scarabceidce MacLeay) are stated not 

 to have the part in question (exscutellati) : but this is not 

 strictly correct, for in these cases the scutellum exists as the 

 point of the dorsolum covered by the prothorax, though 

 it does not intervene between the elytra: in others of 

 this tribe, as Cetonia chinensis, bajida, &c, it separates 

 these organs at their base, though it is covered by the 

 posterior lobe of the prothorax : in Meloe F., the elytra 



a Plates VIII. IX. XXVIII. k' . ■» Audoin, Chabrier, &c. 



c Olivier. He seems also to have thought that neither the Or- 

 ihojrtcra nor Homopterous Hemlptera have this part. N. Diet. 

 (PHist. Nat. x. 112. 



d Plate VIII. Fig. 3. k'. 



