■'Wl THE ('ANADIAN ENT<»MOL(K!IHT. 



obvious, the median lines are belter marked, the s. t. line is preceded by a 

 more obvioui rcddisli shade, and the median shade is well marked in the 

 male and conspicuous in the female. It really looks more like iubterminata 

 (revicta)2i\ first sight ; but closer study shows it a more brilliant instabilit. 



As to sexual structure, the type is very similar to that described for 

 instabiiis, with the following differences : The uncus is not spear-shaped 

 at tip, but is slender and drawn to a long point ; the lower angle of harpe 

 at tip is not drawn out on a line with the lower margin, but forms a slight 

 curve ; the upper angle is a little produced, so that the tip seems, and 

 actually is, broader than it is nearer the base. The clasper is more slender 

 and not so large. 



Again reference is made to Plate VIII, and figure 2 should be con- 

 sulted and comjiared to bring out the differences. These two figures, i 

 and 2, should be compared with those of the following, particularly in the 

 form of the tips of the harpes. 



Only two examples of this form are at hand : The male from Denver, 

 Colorado, IV, 20 ; the female from Ciarfield Co , Colorado, 6,000 feet 

 (David Bruce). 



Under the name ma/ora, I have separated out three males and two 

 females from Calgary, 1\', 24, and \', 2, which may be described as being 

 instabi/is with practically all the red eliminated. It is a dull gray-looking 

 form, with the transverse strigation very dense and coarse, giving a snjoky 

 impression. The median lines are fairly obvious, the t. a. line tending to 

 become a band, while the t. p. line may have a paler following shade. In 

 most cases a broad, obscure diffuse median shade is obvious. The s. t. 

 line is pale, not distinct, and the preceding shade is not well marked nor 

 tinged with red. Altogether the imjiression is of a dull smoky-gray form. 



The genitalia of the male are interesting, and are identical in the 

 three examples studied. Tlie uncus is spear-shaped at lip, as with insta- 

 biiis, but the harpes are quite different. They are decidedly more curved, 

 distinctly narrowed before tip, the lower margin prolonged into a long, 

 curved spine, the upper angle drawn out into a little point, while the 

 ouier margin is distinctly arcuate. A modification of this type of tip 

 occurs in all the other western forms, in contrast to the instabi/is type 

 shown in figures i and 2. Figure 3, representing this sjiecies, should also 

 be compared with the next following. The primary clasper is a long 

 curved hook without obvious dilations. 



An irregularly mottled form, for which I propose the term nubi/ata, 

 occurs in Colorado. It ranges from gray to almost brick-red, the transverse 



