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 antennae are 
longer than the head and thorax, and sometimes 
serrated or pectinated ; whence the generic name, 
from Tipiiov, 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 CERYICORNIS. 
PLATE XXIII. 
Olivier, 66, pi. 2, fig. 8, a, b . — Cerambyx cervicornis, Linn. 
— Merian . Surin ., pi. 40. — 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- 
