454: EXTERNAL ANATOMY OF INSECTS. 
minute tubercle. In many cases the tongue is attended, 
and sometimes sheathed at the base, by two usually mem- 
branous appendages: —these the learned Illiger has deno- 
minated paraglosse ; and I shall adopt his term. You 
will find them frequently attached to the tongue of the 
Predaceous beetles*, and to that of many Hymenoptera 
In the hive-bee and humble-bee they are short, and take 
their origin within the Jabial feelers®: in Euglossa, an- 
other bee, they are long, involute at the tips, and, what 
is not usual with them, very hairy: in the wasp, like the 
lobes of the tongue, they are tipped with a callosity. 
Under this head I may observe to you, that the in- 
sects whose oral organs we are considering besides a 
tongue appear likewise to be furnished with a palate (Pa- 
latum). ‘This, though a part of the roof of the mouth, 
is not precisely in the situation of the palate of vertebrate 
animals, since it seems rather the internal lining of the 
labrum. If you take the common dragon-fly (Aéshna 
viatica), you will find that the under side of this part 
and of the rhinarium is lined with a quadrangular fleshy 
cushion, beset, like the upper surface of the tongue, with 
minute black tubercles, crowned with a bristle. This 
cushion is divided transversely into two parts by a de- 
pression; the anterior or outer piece being attached to 
the labrum, and the other piece to the rhinarium. The 
former has a central longitudinal cavity, black at the 
bottom, on the sides of which the tubercles are flat and 
without a bristle. From its base on each side a spini- 
form process emerges, forming a right angle with it. 
* Pirate XXVI. Fic. 28. i”. 
® Kirby Mon. Ap. Angl. i. t. xii. neut. f. 1. hh. t. xiii. f. 1. ff. 
© Ibid. t. x.¥*, d, 1. f. 2. Bd. 
