362 ENTOMOLOGICAL NEWS [Oct., 'lO 



scarcely relieved against the dark ground. S. t. line slender, pale, usual- 

 ly broken, the outward dents on veins 3 and 4 usually small and never 

 conspicuous, although in some examples they extend to the outer mar- 

 gin. There are no conspicuous preceding marks, sometimes not even 

 a dusky shading although, as a rule, the latter is present. Claviform 

 short, broad, with a smoky outline, not dark-filled. Orbicular varying 

 in size, nearly round, outlined in smoky, sometimes with a dark center, 

 usually concolorous. Reniform large, broad, a little constricted, not 

 well defined, dusky. Secondaries yellowish, smoky at base, with a 

 broad outer blackish border ; fringes yellowish. Beneath, whitish or 

 yellowish, powdery ; with a continuous exterior dusky line crossing 

 both wings and a tendency to a dark area in the s. t. space ; primaries 

 with a blackish lunule, secondaries with a black discal spot. 



Habitat Colorado : Denver, Glenwood Springs, Fort Collins 

 in June and July ; Wyoming; Yellowstone Park in July; Wash- 

 ington : no date nor definite locality ; British Columbia : Ross- 

 land in July. 



A series of ten males and eighteen females is at hand, and 

 the specimens differ little except in depth of ground color. In 

 some the maculation is scarcely at all relieved ; in others it is 

 as well defined as in the average chenopodii. The dull, smoky- 

 luteous ground will serve to distinguish this form from its allies. 



A characteristic feature is the dusky shade of the s. t. space 

 beneath. This, in most cases, is a real band, while in all cases 

 the shading is obvious. 



In sexual structure the species is bizarre. The harpes are of 

 the trifolii type, but the claspers are asymmetrical, compound 

 and, on the right side, the outer process is bluntly and raggedly 

 terminated. The figure must be referred to for a real under- 

 standing of this structure, which is almost exactly duplicated 

 in an altogether different species, M. ortruda, which by its other 

 features is referable to quite a different series of species. 



EXPLANATION OF PLATE XI. 

 Figure I. Mamestra albifusa, male. 

 Figure 2. Mamestra trifolii, male. 

 Figure 3. Mamestra nlbifusa, female. 

 Figure 4. Mamestra trifolii, female. 

 Figure 5. Mamestra oregonica, male. 

 Figure 6. Mamestra morana, "male. 



