152 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



and in some specimens of dentipes is reduced to a small, rounded 

 spot on each side near suture, while in the type of nero, as indicated 

 in the original description, it is entirely absent. The sutural vitta 

 above the median fascia, however, varies much less and differs in 

 form and width in several species, offering a good character for their 

 separation. In some species the blue humeral spot is always present, 

 in others absent, and in one, femoralis, may be present or absent. 

 In the females, generally, the blue markings of the elytra are heavier 

 and the coloration of the ventral segments is darker than in the 

 males. 



The form of prothorax is similar in all the species and nearly as 

 in our robust species of Clerus, but with a much stronger subapical 

 impression, which is very strong at sides and more feeble at middle. 

 The pubescence of the upper side is never very dense and is easily 

 lost. The elytra punctuation seems to be rather constant, but the 

 rugosities between the punctures may vary in the more sparsely 

 punctate forms. The punctuation of the under surface is never 

 dense and is variable even in specimens of the same species. 



The species are apparently rare and poorly represented in collec- 

 tions, and without the assistance of the material in other collections 

 very little could have been accomplished. I have studied 92 speci- 

 mens which are preserved in the following collections and for the 

 loan of which and gift specimens I am greatly indebted to Dr. A. 

 Fenyes, Mr. Warren Knaus, Air. Charles Liebeck, Dr. E. C. Van Dyke, 

 Prof. H. F. Wickham, American Museum of Natural History (through 

 Dr. F. E Lutz), Academy of Sciences of Philadelphia (through Dr. 

 Henry Skinner), Brooklyn Museum, University of Kansas (through 

 Mr. C. P. Alexander), Massachusetts Agricultural College (through 

 Dr. H. T. Fernald), and the United States National Museum. 



Most of the species can be readily separated in the males by good 

 structural characters, but the females are more difficult to distin- 

 guish, and I have used coloration largely in the following table. The 

 measurements of the length of the specimens are from the apical 

 margin of prothorax to the apex of the elytra. Four of the six 

 species of the genus included in Wolcott's synoptic table, 4 but which 

 apparently do not occur in the United States, are omitted 



TABLE OF NORTH AMERICAN SPECIES OF AULICUS. 



1. Head red, prothorax bluish-black at middle, red at sides 2 



Head and prothorax entirely black or bluish black 3 



2. Body below and legs black or bluish-black, except the fifth ventral segment, 



which is red at sides and apex; blue sutural vitta above the median fascia 

 small, sometimes obsolete near base and always much narrower than the red 

 humeral space; claws of male simple; fifth ventral segment of male scarcely 

 emarginate; last dorsal segment subtruncate at apex in the male and broadly 

 rounded in the female monlicola Gorham. 



< Can. Ent., 1910, p. 245. 



