NO. 1988. STUDIES OF NORTH AMERICAN WEEVILS— PIERCE. 377 



as wide as thorax, but not in large females, and longer proportionately 

 than in ovalis. Abdominal suture straight, second not as long as 

 the third and fourth combmed, fifth segment in female long and 

 narrowly rounded at apex, in male shorter and broader at apex. 

 Hind tibise with a double row of spinules at apex. First three tarsal 

 joints with apices of lobes mucronate. 

 Type.—Csit. No. 14632, U.S.N.Mus. 



Genus RHIGOPSIS LeConte (1874). 



Rhigopsis LeConte, Amer. Nat, 1874, p. 459. 



The genus is monotypic based on effracta LeConte. 



TROPIPHOaiNI, new tribe. 



We have undoubtedly had a %\Tong conception of what is a genus 

 in this tribe, but it has become very difficult to reconstruct the 

 classification. The accompanying table is presented m the hopes that 

 it will make some difficult places in the tribe more clear. For the 

 purpose of simpUcity the number of genera is considerably reduced, 

 it beiug considered more advisable to use subgenera where the species 

 groups are so closely alhed. In the following studies considerable 

 mention is made of the form of the nasal plate. This plate is a more 

 or less defined area at the tip of the beak, its base is the apex of the 



beak. 



Table of genera of Tropiphorini. 



Rostrum with scrobes feebly inferior, usually directed toward eyes, or visible from 

 above and badly defined. 



I. Seventh joint of funicle contiguous to club or differently clothed from the other 



joints. Vestiture squamose and pilose pubescent. 



1. Third joint of tarsi feebly emarginate, scarcely broader than the preceding; tarsi 



sparsely setose beneath; beak distinctly separated from the head by a trans- 

 verse depression. Nasal plate more or less obsolete Cimbocera Horn. 



2. Third joint of tarsi bilobed, distinctly wider than second; tarsi spinose beneath 



beak not separated from head by deep depression; nasal plate obsolete. 



Miloderes Casey. 



II. Seventh joint of funicle distant from club; third joint of tarsi broader than second, 



tarsi densely pubescent beneath. 

 1. Scrobes deep, well defined, at least moderately arcuate, passing inferiorly. 

 a'. Scrobes strongly arcuate, passing beneath at a distance from the eyes. 



b^. First suture of abdomen straight; second segment never longer than the two 

 following united; hind tibial mutic; vestiture squamose with intermixed 

 squamiform bristles; nasal plate sharply defined by distmct rim. 



Dichoxenus Horn. 



6^. First suture of abdomen arcuate; second segment usually as long as or 



longer than the two follpwing united; hind tibise mutic. 



d. Vestiture squamose not intermixed with setae or pubescence; anterior 



tibiae denticulate within ; nasal plate depressed but not sharply defined. 



Orimodcma Horn, 

 c^. Vestiture squamose and intermixed with hairs or bristles; anterior tibiae 

 not denticulate within. 



