520 COLEOPTERA OF NORTH AMERICA. 



("lab sparsely liairy, corneous, witliout sutures on upper surface ; with 

 two indistinct sutures on the lower surface ; outer joints of funicle 

 transversely produced, fringed with long hairs ; elytra not aculeate. 



Thysanoes. 



Micracis occurs on both sides of the continent ; Thysanoes in 

 the Atlantic States only. None live on conifers. 



Tribe II.— SCOI.YTII\I. 



The species of this tribe are easily known by the peculiar con- 

 formation of the ventral surface, which is, namely, flattened or 

 concave, and obliquely ascending from the posterior end of the 

 first seg-ment to the fifth ; the first and second segments are 

 closely connate, and the other three are separated by straight 

 sutures, about equal in length, and united are hardly longer than 

 the oblique part of the second segment. The antennal club is 

 pubescent on both sides, nearly solid, and marked with indistinct 

 but strongly curved, or rather angulated, sutures; the scape is 

 short, the first joint of the funicle rounded, the remaining joints 

 (five in number) closely united forming a pedicel to the club. 

 The thighs are stout, the tibiae rather broad and compressed; the 

 front pair are not serrate on the outer edge, which is quite sharp; 

 the outer apical angle is armed with a long curved hook, and the 

 inner angle is nearly rectangular but not armed with a spine; the 

 outer margins of the middle and hind tibite are feebly serrate, 

 they are truncate at tip, and armed with two spines or spurs at 

 the oufe?^ angle, and a much smaller spine at the inner" angle; the 

 tarsi are slender, as long as the tibiae; the third joint is deeply 

 bilobed, the fourth small, the fifth long, with simple divergent 

 claws. 



The side margin of the prothorax is distinctly defined, a verv 

 rare character in Khyncliopliora, and the front co.xae are separated 

 by the prosternum, which is very short in front of the coxae. In 

 some of the species the ventral segments of the % are ornamented 

 with spines, or acute tubercles such as have been observed in 

 Proctorus and certain species of Platypus. 



But one genus, Scolytus, represents this tribe ; species are 

 found in both the Atlantic and Pacific regions. 



