EXTERNAL ANATOMY OF INSECTS. 463 
whole oral machine is fitted for suction ; or where some 
parts appear to be deficient, so that this may be called 
an imperfect mouth. — At first sight one would regard the 
trophi of a bee as of this description; but this is not the 
case, since it has all the ordinary organs, though the 
tongue is unusually long, and looks as if it was made for 
suction ; which, however, as you have been informed, is 
not the case. 
There are five kinds of zmperfect mouth to be met with 
in insects that take their food by suction, each of which 
I shall distinguish by a separate denomination. The first 
is that of the Hemiptera Order :—this: 1 term the Pro- 
muscis ; the second is that of the Diptera, which with 
Linné I call Probvosezs ; the third, peculiar to the Lepido- 
ptera, is with me an Anétlia; the fourth, which I name 
Rostrulum, is confined to the Aphaniptera Order, or 
genus Pulex L.; and the last is the Rostellum, which 1 
employed to denote the suctory organs of the louse tribe 
(Pediculide). 
i. Promuscis*.—-The organ we are first to consider 
has usually been denominated Rostrum: but since that 
term is likewise in general use for the snout of insects of 
the weevil tribes (RAyncophora), 1 think you will concur 
with me in adopting the one here proposed, for the very 
different oral instruments of the Hemiptera. IMlliger has 
employed promuscis to denote those of bees>: but since, 
as I have just observed, they consist of all the ordinary 
organs, they seem to require no separate denomination : 
the term, therefore, may be applied to represent a diffe- 
rent set of trophi, without any risk of producing confu- 
4 Prate VI. Fic. 7—9. x, b,c’, d’. > Magaz. 1806. 
a 
