400 COLEOPTERA OF NORTH AMERICA. 



Stenotrachelus 07^Hatus (Say) and Scotodes americanus Horn 

 are the only representatives of this tribe in our fauna; the former 

 extends from Canada to Alaska, the latter occurs in the AVhite 

 Mountains. 



This tribe is remarkable for presentinp: the first instance of the 

 cleft form of claws, which reappears subsequently in the Anthicidae 

 in the genus Nematonyx, and becomes very general in the families 

 Mordellidas and Meloidae; it is very doubtful whether these two 

 genera should not be separated as a distinct family and placed 

 just before Anthicida3. 



Tribe V.— IVOTHIXI. 



Head deflexed; antennsE slender or feebly subserrate; maxil- 

 lary palpi with the last joint large, dilated, nearly cultriform ; 

 anterior coxte conical, contiguous, trochantin distinct; middle 

 coxse closely approximated, the cavities open externally with 

 distinct trochantin; tibial spurs small but distinct; tarsi with 

 the penultimate joint prolonged in an emarginate lobe beneath 

 the last joint; claws with a broad, rectangular dilatation at base, 

 the apical portion cleft in the male. 



This tribe contains in our fauna but one genus, Nothus, repre- 

 sented by one species on each side of the continent. They resem- 

 ble Telephori in appearance, and are found on flowers. In the 

 males the posterior femora are curved, and the tibiae armed with 

 an acute process on the inner edge near the tip. 



Tribe VI.— MYCTERINI. 



Head horizontal or slightly inclined, slightly narrower behind 

 the eyes; antennae slender, subserrate beyond the third joint; 

 eyes oval, subtruncate in front; prothorax narrower than the 

 elytra, the lateral margin indistinct; anterior coxa? small, coni- 

 cal, contiguous, vi^ithout trochantin; middle coxag small, rounded, 

 inclosed by the sterna without visible trochantin ; posterior coxos 

 transverse, separated by an acute intercoxal process; legs slender, 

 tibiae with small spurs; tarsi slender, the penultimate joint pro- 

 longed in a membranous lobe; claws armed with a broad basal 

 dilatation. 



The genera constituting this tribe form two natural groups, as 

 follows: — 



