COLEOPTEROUS INSECTS. 245 



probably serve to render it more steady by adher- 

 ing to the substance into which it is inserted. The 

 right-hand figure represents this ovipositor as it 

 appears in P. armillatus. 



The largest and most striking of these insects 

 compose the genus Prionus. Their antennse are 

 longer than the head and thorax, and sometimes 

 serrated or pectinated ; whence the generic name, 

 from itpuov, a saw% The terminal lobe of the max- 

 illae is as long as the first two joints of the palpi, 

 and the body is depressed, with the thorax square 

 and spined or dentate on its edges. 



PRIONUS CERVICORNIS. 



PLATE XXIII. 



Olivier, 66, pi. 2, fig. 8, a, b. — Cerambyx cervicornis, Linn. 

 —Merian. Surin., pi. 48. — Macrodontia cervicornis, Lepel. 

 et Serv. 



Although this insect is surpassed in size by one 

 or two other species of Prioni, it is the most re- 

 markable of the larger kinds, owing to its conspicu- 

 ous projecting mandibles, and the curious markings 

 of the elytra. The prevailing colour of the head 

 and thorax is rust-brown; the former bears two 

 elevated longitudinal lines, and the latter has three 

 strong acute spines on each side, the two anterior 

 ones being rather remote from each other, and the 

 margin between them dentate. The mandibles of- 



