324 CURCULIONID^E. 



[LeConte. 



closed by the meso- and metasternum. Side pieces of mesosternum diagon- 

 ally divided; of the metasternum, narrow dilated in front, the outer angle 

 making a sinuosity in the side margin of the elytra. Ventral segments 

 unequal; first and second longer; third 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 intercoxal process is broad. 



The proportions of the ventral segments permit the recognition of two 

 groups. 



A. Ventral segments not very unequal; postocular lobes 



of prothorax obsolete Pliytoiiomi. 



Articular surface of hind tibia3 well-defined, ter- 

 minal PHYTONOMUS. 



Articular surface of hind tibiae 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 than the first LJSTRONOTUS. 



Tibiae feebly mucronate; first joint of funiculus as 



long as, or but little longer than the second MACROPS. 



PHYTONOMUS Sch. 



A. Beak short and thick, 1st and 2d joints of funicu- 



lus equal , 1. opiums. 



B. Beak longer and more slender, 1st joint of funicu- 



lus stouter and frequently longer than second: 



Elytra much wider than base of prothorax 2. 



" scarcely " 2. elongatus. 



2. Prothorax pubescent without scales 3. 



" scaly with long hairs intermixed 3. setigerus. 



" scaly without hairs, scales very small 5. 



3. Pubescence coarse 5. pubicollis. 



" very fine 4. 



4. Pubescence mottled, elytra tesselated... 6. Castor. 



pale-green, nearly uniform 7. nigrirostris. 



5. Scales golden -brown, sides of prothorax rounded.. 4. comptus. 

 Scales dirty-gray, sides of prothorax nearly straight 8. quadricollis. 



1. P. opimus, n. sp. 



Robust, black, densely finely punctured, and covered with gray scales, 

 having a metallic lustre ; sparsely and indistinctly pubescent. Beak one- 

 half longer than the head, stout, curved, antennal grooves deep, suddenly 

 flexed downwards ; there is a small oblique groove each side near the tip, 

 a short nasal furrow, and another between the eyes which are transverse. 

 The funiculus of the antennae has the first joint nearly as long as the second, 

 which is nearly equal to the three following united. Prothorax sub- 

 quadrate, a little wider than long, rounded on the sides in front, and 

 feebly constricted ; disc very obsoletely channeled. Elytra much wider 



