LeConte.J TROPIDEKmi. 393 



3. Sides of beak not dilated; antennae very long Ischnocerl. 



" " dilated over the antennal cavities Tropideres. 



Group I. Ischnocerl. 



Beak longer than the head, dilated at tip; antennal cavities large, lateral, 

 limited above by a small, elevated line, which descends to the inferior mar- 

 gin of the eyes. Eyes longitudinal, elliptical, rather coarsely granulated. 

 AntenntB very slender, longer than the body in (j^; two-thirds as long in 

 9 ; first joint very short; second twice as long as first, and more than one- 

 half as long as third; 9-11 broader, forming a compressed, loose, oval club. 

 Tarsi with the first joint long; second triangular, emarginate, with pro- 

 longed angles; third as wide as the second, bilobed; claws armed with a 

 long, acute tooth at the middle. 



ISOHNOOERUS Schonh. 



1. I. infuscatus Fahraeus, Sch. Cure, v, 193; Meconemus tuberculatus 

 Imhoft' and Labram, Gen. Cure. 1, 40. 



Mexico, extending into the Southern States as far as South Carolina. 

 In the Mexican specimens the pubescence is somswhat paler and more 

 dense; it is Ischnocerus macrocerus of Dejean's Catalogue. 



This is a narrow species, with the base of the prothorax truncate; there 

 is a trace of a second transverse raised line between the base and the ante- 

 basal ridge ; the latter is situated about one-fifth from the base, slightly 

 sinuate, and forming an obtuse angle at the middle; flexed obliquely for- 

 wards on the side, where a distinct lateral angle is formed behind the middle. 

 The pubescence is yellowish brown, mixed with pale gray, and does not 

 exhibit any distinct pattern. Length 6.8-10 mm.; .37-.40 inch. 



Group. II. Troplderes. 



The sides of the beak in the insects of this group are dilated over the 

 antennal cavities, which are therefore not visible from above. The form 

 of the antebasal ridge differs in each genus, and in conjunction with the 

 antennal club and tarsal claws affords easy characters for distinguishing the 

 genera. The eyes are entire, either rounded or oblique. 



Antennal club narrow, not compressed 2. 



" " oval, compressed 3. 



3. Prothoracic ridge strongly angulated and touching 



the base at the middle ; claws simple GONOTROPIS. 



Prothoracic ridge straight at the middle, base deeply 



biemarginate ; claws acutely toothed EURYMYCTER. 



3. Eyes oblique, slightly oval, beak short TROPIDERES. 



Eyes rounded, beak longer, antenn* (^ very long.. ALLANDRUS. 



GONOTROPIS n. g. 

 Body rather robust and convex. Beak longer than the head, gradually 

 narrowed to the middle, then widened to the tip, which is truncate with 



FKOC. AMER. PHILOS. SOC. XV. 96. 3x » 



