EXTERNAL ANATOMY OF INSECTS. 525 



thorax and fore-breast exactly admitting the base of the 

 latter, which are quite concealed under the former. In 

 Cryptocephalus and Chlamys, kindred beetles, when at 

 rest they are withdrawn, except their scape and pedicel, 

 with the head within the cavity of the protJiorax. I n 

 others they are turned under the head, without any par- 

 ticular cavity for their reception; as in many moths, 

 Apion, &c. In most of the Lamellicorn beetles their sta- 

 tion is in the cavity formed by the eye and the throat, 

 the knob forming, an angle with the rest of the antenna. 

 In Heterocerus they follow the contour of the eye a . In 

 BrentuSf a genus of weevils remarkably long and slen- 

 der, they are turned back and received by a slight longi- 

 tudinal cavity of the rostrum ; but in those of this tribe 

 {Curculia 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 {Muscidcc) a vertical frontal cavity receives 

 the antennas, which point downwards during repose b . 

 Cryptocerus, a very remarkable ant, has on its head a 

 sino-ular square plate, the sides of which form a deep 

 longitudinal cavity: in this cavity the antenna?, 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 antenna? c ; 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. 



a Plate XXV. Fig! 35. h De Gcer vi. t. If. 5. 



c Plate XI. Fig. 21. 



