360 MODERN CLASSIFICATION OF INSECTS. 



(^^.43.1. Prionus coriarius), and distinguished by the emarginate 

 eyes ; the upper lip obsolete, or very small {fig. 43. 2.) ; the head 

 not narrowed behind into a neck; the mandibles very large, and 

 robust, especially in the males; the internal maxillary lobe small, or 

 obsolete (^fig. 43. 3.) ; the palpi moderately long ; the labium small 

 (^^.43.4.); the antennae are inserted between the base of the 

 mandibles and the eyes, but their basal insertion is not immediately 

 surrounded by the notch of the latter ; the thorax is generally trans- 

 verse or square, and toothed at the sides. 



The perfect insects are generally of dark and obscure colours ; 

 they are very inactive during the day, but take flight in the twilight; 

 they are found upon the trunks of trees ; and M. Lacordaire informs 

 us [Ann. Soc.Ent. France, torn, i.), that the large Prionus cervicornis 

 saws off the branches of trees with its large mandibles. 



Rosel has described and figured the transformations of Prionus 

 coriarius [Insect. Belustig. voX.n., Scar terrestr. tab. 2.). The larva {fig. 

 42. 5., reduced from Ilosel's figure) is a broad, flattish, white grub, 

 with the body gradually narrowed towards the posterior extremity, 

 and divided into a head of moderate size, thirteen segments, and an 

 anal lobe ; the first segment is short, the second large, and subde- 

 pressed ; the head is capable of being considerably retracted into the 

 first thoracic segment ; the mandibles are very powerful, but small 

 and triangular, and are employed in gnawing the wood, upon which 

 the insect feeds; the three pairs of legs are very minute, and attached 

 to the three thoracic segments ; the seven following segments are 

 also furnished with fleshy tubercles, which are alternately applied to 

 the surface of the object upon which it is placed. When full fed, it 

 forms a large cocoon, chiefly composed of chips of gnawed wood, 

 wherein it passes its pupa state ; in which it off'ers no other peculiarity, 

 except that the antennoe are laid along the sides of the body, over 

 the elytra. It is also observed that, before the larva undergoes its 

 change to a pupa, it has the instinct to bore its hole close towards 

 the outer surface of the tree, so that the perfect insect may the more 

 readily effect its escape. 



The species of this family are for the most part extra-European, 

 three only being found in this country, belonging to the genera 

 Prionus, Spondylis, and Asemum. 



The structure of the genus Spondylis {fig. 43. 6. Spondylis 

 buprestoides ; 43. 7, under side of its head ; 43. 8. maxilla ; 43. 9. 



