524 EXTERNAL ANATOMY OF INSECTS. 
der, they are turned back and received by a slight longi- 
tudinal cavity of the rostrum; but in those of this tribe 
(Curtulio L.) in which the clavolet forms an angle with 
the long scape, this latter part, bending back, is laid up 
in an oblique channel of that part; and the former, 
pointing in the contrary direction, is folded upon it. In 
many flies (Muscide) a vertical frontal cavity receives 
the antenne, which point downwards during repose?. 
Cryptocerus, a very remarkable ant, has on its head a 
singular square plate, the sides of which form a deep 
longitudinal cavity: in this cavity the antennae, quite 
concealed, repose in safety. A cavity equally remark- 
able is exhibited by the water-scorpions, particularly 
Belostoma, in which is a very deep kidney-shaped box, 
between the eye and throat, to receive and defend its 
singular antennee>; which, when they are reposing, is 
closed by the exterior harder joints, and from which it 
seems as if they turned out, like a sentinel out of his box. 
In some aquatic genera of beetles, as Gyrinus, Parnus, 
&c. they are withdrawn within a lateral cavity of the 
same part, and are defended from the water externally 
by the auricle at their base*. The flabellated and la- 
mellated antenne, previous to their being folded for re- 
pose, close all their plates; which in action are as widely 
expanded as possible, so as to form a knob; and in some 
the middle piece is entirely concealed, as if in a box. 
In broken antennz, or those in which the clavolet forms 
an angle with the scape, the former is folded upon the 
latter, with its point downwards. 
II. Subfaciesx—Having dispatched the Facies, or up- 
4 De Geer vi. f. 1. f. 5. > Pirate XII. Fre. 21. 
* bid. Fie? 29. a: 
