470 COLEOPTERA OF NORTH AMERICA. 



nate at tip; meiituin large, flat; ligula feebly or not prominent; 

 palpi much less developed than in Hylobiini. Tibiae more or 

 less mucronate at tip; articular surface lateral; corbels wanting; 

 claws connate at base, or at least approximate. Antennse some- 

 times feebly geniculate; joints of funicle gradually broader; club 

 elongate-oval, aunulated, pubescent, and sensitive. 



The other characters are variable. The beak is either short 

 and thick, or long and cylindrical, but not slender; the tarsi are 

 dilated and spongy beneath, with the third joint broad and bilobed, 

 or only hairy, with the third joint shorter and emarginate. The 

 first and second ventral segments are long and connate; in the 

 elongate species the other segments are moderately long; in the 

 species with thick short beak they are shorter. The antennae are 

 inserted at a variable distance from the tip of the beak. 



Sexual differences are not apparent in the short-beaked species; 

 in some of the elongate forms the beak is longer in the female. 



Gradational characters are observed in the form of the beak, 

 antennas, tarsi, and claws, varying by almost insensible degrees, 

 so as to render the classification of this tribe very difficult. After 

 several efforts, we are only able to offer the following table for 

 the identification of the genera we have examined : — 



Beak flat, stout, more or less grooved, somewhat dilated at tip ; protliorax 



angulated on the sides near the tip, tlien suddenly constricted. Antennse 



rather stout, feebly geniculated ; ventral segments 3-5 shorter than in 



the subsequent genera. Tarsi usually not spongy beneath, in which 



case the third joint is emarginate, not bilobed. . 2. 



Beak cylindrical, rather stout, not dilated at tip; prothorax usuall}- not 



angulated at the side ; ventral segments 3-5 not so short ; tarsi usually 



spongy beneath, claws connate at base. 4. 



Beak cylindrical, varying in length, generally smoother than in the pre- 



cedi3ig genera ; antennae less approximate to the tip ; prothorax not 



angulated at the sides ; ventral segments 3-5 not very short ; tarsi 



spongy beneath, third joint broad, bilobed; claws connate at base; 



second joint of funicle equal to first. Lixus. 



2. Presternum without spines in front of the coxae. 3. 

 Prosternum armed with short spines in front of the cox?e. 



Centrocleonus. 



3. Beak strongly carinate, third joint of hind tarsi not spongy beneath. 



Stephanocleonus. 

 Beak feebly carinate, third joint of hind tarsi broad, spongy beneath. 



Cleonopsis. 



4. Hind tarsi with third joint shorter, emarginate, not spongy beneath. 



Cleonaspis. 

 Hind tarsi with third joint broader, bilobed, spongy beneath. Cleonus. 



