CURCULIONIDAE. 467 



tliird and fourth shorter ; fifth as long as the two preceding 

 united; sutures straight; the lateral angles of the first segment 

 are covered by the elytra, and the intereoxal process is broad. 



The proportions of the ventral segments permit the recognition 

 of two groups. 



A. Ventral segments not very une(xual ; postocular lobes of protliorax 



obsolete. Phytonomi. 



Articular surface of hind tibije well defined, terminal. Phytonomus. 

 Articular sui-face of hind tibije ill-defined, oblique. Lepyrus. 



B. Ventral segments very unequal ; third and fourth short, united equal 



to one of the others. Listroderi. 



Tibiae strongly mucronate ; second joint of funiculus much longer tluin 



the first. Listronotus. 



Tibiae feebly mucronate; first joint of funiculus as long as, or but 



little longer than the second. Macrops. 



Phytonomus occurs on both sides of the continent; Lepyrus in 

 Kansas and Canada. Listronotus and Macrops have a general 

 distribution. 



Tribe II.— EMPHYASTIIVI. 



This tribe is evidently closely related to Hylobiini, and agrees 

 with it in the structure of the mouth, but differs from it, as from 

 all other tribes in our fauna, by the peculiar form of the tibiui, 

 which are fitted for digging. 



The front tibise are compressed, slender, subsinuate, prolonged 

 beyond the articulation of the tarsus into a broad process, rounded 

 at tip, and concave beneath; the spur is small and straight; the 

 middle tibise are roughly tuberculate and setose, with the apical 

 margin repand, dilated on the outer side, and armed with a 

 straight fixed spur at the inner side; the hind tibiae are bent out- 

 wards, tuberculate and setose; much thickened towards the tip, 

 with very largo and acutely margined corbels. Tarsi sparsely 

 setose beneath, and not spongy; third joint not dilated nor bi- 

 lobed ; fourth joint moderate in size, claws slender simple, and 

 divergent. 



The antennae are geniculate; funiculus V-jointcd; first joint 

 longer; 2-7 gradually broader, forming a perfoliate stem uniting 

 with the club, which is oval, annulated, and pubescent. Beak 

 stout, shorter than the protliorax, deeply grooved ; antennal 

 grooves extending to the eyes, which are small, nearly round, 

 and coarsely granulated. 



