4-G6 EXTERNAL ANATOMY OF INSECTS. 



the front appears to be divided. Look below these, and 

 you will there discover the upper-lip : and from this you 

 may follow the promuscis till it gets beyond the forelegs, 

 when it takes a direction perpendicular to the body a ; a 

 circumstance which has given rise to the above false no- 

 tion. Though in Coccus, Chermes, &c. this instrument is 

 short, in some Aphides it is longer in proportion than in 

 any other insect. In A. Querents it is three times the 

 length of the body; so that when folded, it stretches out 

 beyond it, and looks like a long tail b ; and in A. Abietis 

 it even exceeds that length c . 



ii. Proboscis d . — Linne long since, and after him Fa- 

 bricius, has employed this term to designate the oral in- 

 struments, or rather their sheath, in the Muscidce and 

 some others, calling the same organ, when without fleshy 

 lips, rostrum and haustellum: but as the parts of the 

 mouth in all true Dijptera (for Hippobosca and its affinities 

 can scarcely be deemed as co-ordinate with the rest), are 

 analogous to each other ; although in some they are stiff 

 and rigid, in others flexile and soft, and in GUstrus (ex- 

 cept the palpi) mere rudiments, — the same appellation 

 ought to designate them all. I am happy to find that 

 M. Latreille agrees with me in this opinion ; and to his 

 sensible observations on this head, if you wish for further 

 information, I refer you e . The mouth of Dipterous in- 

 sects appears to vary in the number of pieces that it pre- 



a De Geer iii. 137—. t. ix.f. 4. 

 b Reaum. iii. 335. t. xxviii./. 8 — 14. 

 c De Geer iii. 117. t.vm.f. 22. b. 

 11 Plate VII. Fig. 5, 6. a', b', c', d\ 

 e N. Diet. d'Hitt. Nat. iv. 253. 



