68 ENTOMOLOGICAL NEWS. [March, 



Pausing now to discuss these differences, < 



I have not found any variations in the statements for characters numbered 



1 to 5 ; this, of course, is merely another way of stating that I have taken 

 the superior appendages as the chief specific characters, a course which I 

 believe is fully justified by the material studied. 



For No. 6, one male fraterntis, Ind., had the divergence greater, 

 although not as great as in externus, thus representing a variation of 5%, 

 while two males crassus, Ohio, had the divergence no greater than that 

 of the superiors (10%). 



No. 7 : the edge but very slightly longer than either branch i (^ frater- 

 nus, Ark. (5%). 



No. 8 : in i ^ frater7ius, Ark., not quite contiguous (6%); 10 $ '^ fra- 

 iernus have the angle of divergence of the tips 90°, 7 ? ?, mostly Ind., 

 about 60°; iov externus i 9. 111-?, is distinctly \\ke fraternus with the 

 angle of divergence 90°, i 9* has the tips slightly divergent at about 60°. 



No, 9. fraternus : absent i9, Ark., only a trace present i 9, Ohio, 

 extends to basal three-fourths i 9) II'- \ well developed in i 9 externus* 



No. 10: not interrupted in ^fraternus (3 ^ Ohio, Ind., 111., i (f i 9, 

 Ark.) (13%), interrupted in i 9 externus*, barely interrupted i f^ crassus, 

 Ohio. 



No. ir. Fraternus: i 9 Ind., i 9 Ark. spines absent, i 9 Ind. spine 

 absent on right side, rudimentary on left (total I7>^ 'ft ); marked difference 

 in length of right and left spines i 9 Ohio ; spines black in 8 9 , yellow in 



2 9 111. 



No. 12 : a yellow stripe or line in 7 /raterjius {iS'/f), viz. : on the basal 

 third of ist and 2nd, basal fourth of 3rd tibiae, 3 (^, 111., Ind.; on the basal 

 fifth of 3rd tibiae only 2 (^ 111., i 9 Ohio ; on basal half of all tibiae, i ^f 

 111. In externus this stripe may be almost as long as the tibiae, 3 9 HI- \ 

 or on the basal two-thirds of the ist, basal half of 2nd and 3rd, i cf i 9 

 111., I 9 Tex.; or on the basal half of the ist tibiae, basal third of 2nd and 

 3rd, 3 (^ 111. ; or on the basal half of 3rd tibiae only, i 9 •* 



The differences between these three species which have thus 

 far been considered are subject at the most to a variation of 20 

 per cent, and can, therefore, be considered specific, although to 

 varying degrees. I have also compared these three species as 

 regards a number of other structural and colorational differences 



* This female, which I have included in externus because it agrees in 

 characters Nos. 11 and 12, occupies quite an intermediate position since 

 it has character 8 like both externus and. fraternus, 9 as in fraternus and 

 10 as in crassus. It was marked as having been taken in copula with a 

 (^ which I unhesitatingly name fraternus ; the locality is probably Illinois, 

 the date June 29, 1895. I think it quite likely that this female may be a 

 hybrid. 



