12 NORTH AMERICAN 



Vancouver Island, British Columbia, 7. 



The most salient features in the differential characters of the two 

 species, nitidulus and zephyrus, are the structure of the antennae, 

 punctuation of the head, pronotum, and elytra, structure of the hind 

 tarsi, relative lengths of the pronotum and elytra, the degree of 

 emargination of the latter behind, and slight differences in the sexual 

 characters of the male and female. The antenna! club is much more 

 slender and paler in color in the latter species. 



The species are evidently closely allied, and whether the insular 

 conditions under which zephyrus has existed, have caused differences 

 as announced above, in individuals originally of the same species, is 

 an interesting problem, which time alone can aid us in solving. 



The spots in zephyrus begin slightly behind the middle, are nearly 

 circular in outline, and are distinctly nearer the external than the 

 internal edge of the elytron. 



STENUS Latreille. 



The species of this genus are extremely numerous, and often very 

 closely allied. Our representatives are all included in the three fol- 

 lowing divisions : — 



Abdomen strongly and distinctly margined. 



Eacli elytron having a spot of orange tint near tlie middle of its disk. ...A. 



Elytra immaculate i». 



Abdominal border reduced to the mere line of juncture of the dorsal and 



ventral surfaces of the segments, only distinct on the first segment, and, 



in some cases, at the bases of the remainder .*C. 



Division A. 



In this division the species are few in number, and among the 

 largest of the- genus. They are recognizable at once by the more or 

 less reddish-orange colored spot, of form varying according to the 

 species, situated near the middle of each elytron. The legs are, as 

 a rule, long and very slender, and they are nearly all rapid in their 

 movements. 



The species occurring in North America, north of the Mexican 

 boundary, are seven in number, and may be classified as follows : — 



Femora black. 



Spots extremely small, beginning distinctly behind the middle of the 



elytron; form very slender 1. pillictigei'. 



Sjnils much larger, beginning at the middle of the elytron; form more 

 robust; spots sometimes angulated 2. bipuilCtatllS. 



