EXTERNAL ANATOMY OF INSECTS. 489 



In the Homopterous Hemiptera they run parallel nearly 

 with the rhinarium or nostril-piece. In the Hymenoptera 

 they are almost always ample, but they are confined to 

 the lower side of the eye. In Sir ex Gigas, and others of 

 that genus, the cheek at the base of the mandible is di- 

 lated so as to form a rounded tooth below it. In the 

 Capricorn-beetles it is considerable, and sometimes ter- 

 minates, at the base of the mandible, in two or three 

 notches. In Scaurus and Eurychora, darkling-beetles, 

 the cheek below projects into a lobe that covers the base 

 of the maxilla. But the animal distinguished by the 

 most remarkable cheeks is a species of Pliryganea L. 

 {Pliryganea personata Spence) ; for from this part pro- 

 jects a spoon-shaped process, which curves upwards, and 

 uniting with that of the other cheek, forms an ample mask 

 before the face, the anterior and upper margin of which, 

 in the insect's natural state, are closely united ; and the 

 posterior part being applied to the anterior part of the 

 eye, causes the face to appear much swoln. It looks as 

 if it was a single piece ; but upon pressing the thorax it 

 opens, both above and in front, into two parts, each con- 

 vex without and hollow within, and each having attached 

 to its inside a yellow tuft of hair resembling a feather. 

 The use of this machinery at present remains a my- 

 stery a . 



vii. Tempora b . — The temples ( Tempora) are merely 

 a continuation of the cheeks to the posterior limit of the 



a This insect was taken both at Matlock and Exmonth. The body 

 and thighs are of a light-brown, wings testaceous, legs pale ; antennae 

 between setaceous and filiform, two-thirds the length of the body ; 

 first joint not much thicker than the rest, 



" I'LATES VI. VII. R. 



