AMERICAN COLEOPTERA. 255 



As there are many species already well known to all collectors, 

 these will be taken as the standards in speaking of color, so that the 

 idea may be better conveyed. 



The lateral margin of the elytra and basal line unite at the hume- 

 rus, forming either a distinct angle or a regular curve. To avoid 

 repetition of description, the expression in the former case will be 

 "basal line angulate at humerus," and "arcuate at humerus" in the 

 latter. The anterior femur of the male may have near the base a 

 feeble tooth, or it may be subangulate, that is, suddenly narrowed, or 

 it may be entirely simple, being gradually narrowed from the thickest 

 portion toward either extremity. These expressions seem not to need 

 any further explanation. 



A. — Middle tibise % without pubescent space at tip. Third joint of antennse 

 not longer than the fourth, (except in 1 and 2). 

 Abdomen impunctured and glabrous. 



Thorax narrower at base than the elytra, sides distinctly sinuate, basal 



impressions deep, surface irregularly punctured 1. validlis. 



Thorax as broad at base as the elytra, sides not sinuate, basal impressions 



very feeble, surface densely punctured 2. tonieiltOSUS. 



Abdomen sparsely punctured and pubescent over the entire surface, 1. 



1. — Prosternum not margined at tip, thorax not sinuate_ 2. 



Prosternum margined at tip, thorax distinctly sinuate ,.3. 



2. — Thorax with coarse punctures very irregularly disposed. Legs black... 4, 



Thorax more finely and densely punctured, subopaque. Legs red 6, 



4. — Prosternum punctured between the coxfe, elytra coarsely and rather 



densely punctured. Thorax as wide as base of elytra 6. 



Prosternum impunctured, elytra finely punctured, thorax narrower 7. 



6. — Marginal line of elytra forming an angle with the basal line, margin of 



thorax not thickened 3. piirpuricolli». 



Marginal line of elytra regularly curved at base, margin of thorax 

 thickened, especially toward the base. 

 Elytral intervals alternately more convex, but similarly punctured. 



4. alternatiis. 



Elytral intervals equal 5. niger. 



Strise of elytra broken into short lines 0. intfrruptus. 



7. — Head greenish, thorax feebly bronzed, body and elytra black. 



7. harpalinu!^. 

 5, — Thorax narrower at apex than base, and with narrow red margin. 



8. impunctifrons. 

 o 



o. — Thorax with impunctured spaces or unequally punctured. 



Mandibles elongate, deflexed; thorax with very coarse, deeply im- 

 pressed but sparsely placed punctures 9. maxilloSUS. 



Mandibles normal in form. 



Epipleurse pale, thorax distinctly sinuate 10. circunicinctus. 



Ej^ipleurse concolorous, thorax not sinuate 11. texauus. 



Thorax equally punctured. Epipleurse dark 8. 



