LONG-HORNED WOOD-BORERS. 



161 



Snb-family PRIONIDES. 



The Prionides are generally large, slow-mov- 

 ing insects, flying only in the evening, and 

 usually of nniforni black or brown colors. • They 

 are distiugusliotl from the other Longicornes 

 chiefly by their sub-quadrate thorax, the sides 

 of which form a sharp margin, which is usually 

 divided into two or three teeth. The thighs 

 are never clavate or suddenly enlarged at the 

 end, as they are in many of the species of the 

 other sub-families. The eyes are usually coarse- 

 ly granulated, and the middle cotyloid cavities 

 are widely open on the outer side. Some of 

 the tropical species are of gigantic size, being 

 five or six inches in length. The larv.ne are 

 broad and somewhat flattened, and have six 

 very small but distinct feet. They inhabit the trunks and roots of trees. 



The subfamily is named after the genus Priouus, of f^ig. 74.j 

 Geoffroy, a term derived from a Greek word meaning a 

 saw, and applied to these insects on account of the long 

 saw- toothed antennae of many of the species, especially of 

 the males. 



Pinoxi3 i.ATicoi.us, Drury 

 male— after Riley. 



~ Pnpa of Prionub — 



Larva of Prionub— after Riley. after Kiley. 



The following are the principal N. American genera : 



A. AntenntB not longer than the thorax ; thoracic margin without teeth ; tarsi simple Paraxdra. 



A A. Antennte nuich longer than the thorax; t«rsi apongy beneath, with the third joint bilobed. 

 JB. Eyes coarsely granulated ; colors uniform. 

 C. Thoracic niar<:iu prominent ; side piece.i of the metastemom parallel. 

 D. Eyes not closely approximate; antennal jointa imbricate ; teeth of the thoracic margin short 



and flattened. Body robust Pkioxus. 



D D. Eyes very large, approximate above and below ; thoracic t-eeth spine-shaped. Body elon- 

 gate. 

 E. Thorax much narrowed behind; margin three spined, the anterior spine shortest. .M joint 



of the antenna; as long as the 4th and .")th united Dekourachus. 



E E. Thorax nearly square ; margin 3-spined, the hindermost spine shortest ; 3d joint of an- 

 tenna; but little longer than the 4th -.. .Orthosoma. 



D D D. Eyes very wide apart, but slightly notched ; size very large ; thoracic margin usually 

 many toothed. 

 F. First joint of antennte mach shorter than the third Ekoates. 



