632 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



pared with such allying features as presence of hemelytral suture, 

 marginal pegs on the head, secondary sexual differences, general 

 punctation, small size, and general shape. 



Although this genus appears to be readily separable into species 

 units, the problems of correctly associating older names with them 

 has been vexing. The chief reason for this appears to lie in the fact 

 that the small size of the specimens has deterred some authors from 

 making critical enough studies of specimens to locate the real diag- 

 nostic features. Consequently, without a personal study of the types, 

 the author feels that this must be considered the most tentative part 

 of the present work. Perhaps with the points established here the 

 author or other workers may have opportunity to examine the types 

 and be able to straighten out the nomenclature. 



Until corrected by Hart (1919), workers generally had the sexes of 

 this genus confused. They described the females as having prominent 

 spines on the ventral surface of the femur, whereas these secondar}'- 

 sexual modifications in reality belong to the males. The male also 

 generally has the anterior lobe of the pronotum more tumid than do 

 the females. 



From specimens available, males of som^e species of Amnestus were 

 arranged according to the secondary sexual characteristics of the 

 legs, as follows: 



la. Anterior tibia distinctly angled (sometimes obtusely so) or spined midven- 

 trally (figs. 131, 132). 

 2a. Anterior tibia ventrally with spine at basal fourth (fig. 132). 



3a. Subapical ventral spine of posterior femur a third or more of tibial length 



(fig. 164) pusillus 



3b. Subapical ventral spine of posterior femur shorter than vertical height 



of femur basidentatus 



2b. Anterior tibia without subbasal spine ventrally. 



4a. Posterior femur dorsally angulated subapically (fig. 162). 



lateralis, pusio, radialis 

 4b. Posterior femur dorsally without subapical angulation. 



5a. Medioventral spine of anterior femur conical, with a prominent 

 lateral spine near its midlength (i.e., very unequally bifurcate) 



(fig. 131) spinifrons 



5b. Medioventral spine of anterior femur simple or feebly, equally 



bifurcate subferrugineus 



lb. Anterior tibia neither spined nor distinctly angled midventrally. 



6a. Anterior femur with midventral spine sim.ple . diminuatus, explanatus 

 6b. Anterior femur with midventral spine furcate. 



7a. Subapical spine of posterior femur flattened, bifid. 



championi, cribratus, forreri 

 7b. Posterior femur with ventral spine not bifid, either spine-, needle- or 

 blade-like. 



brunneus, foveatus, lautipennis, pallidus, trimaculatus, uhleri 



