88 BULI^ETIN 64. 



consequence of the inefficiency of the harpe the uncus has re- 

 mained comparatively unmodified and strong chitinous hooks 

 have been developed on the penis. The hooks on the penis are 

 undoubtedly correlated with chitinous processes in the vagina. 



20. Crambiis albdlus. The wings are narrower than in the 

 preceding species. Here the strongly reduced harpe is evidently 

 correlated with the chitinous processes at the external orifice of 

 the vagina. The valve, uncus, and lower limb are about the 

 same as in C. topiarius. Chitinous processes on the penis would 

 appear superfluous, as the harpe is made very efficient by the 

 processes on the vagina, hence there is no such development as 

 occurs in C. topiarius. The genital plate of the female is more 

 specialized than in C. topiarius. 



22. Crambus agitatellus. The venation of this species is 

 almost the same as in C. innotatellus ; the difference being no 

 greater than might be expected within specific lines. The clasps 

 are nearly' equal and are not so specialized as in C. intiotatelltis. 

 The same is true of the uncus and the genital plate. On the 

 penis a stout recurved hook has been developed. The antennae 

 are more specialized than in C. innotatellus. These two species 

 possess a nearh- equal degree of development. This species is 

 placed here because it leads most naturally to the following 

 species and they are most closely related to the most specialized 

 forms ; it is really the most generalized species of this group. 



23. Crambus niiniviellus. In this species the fore wings are 

 most highly specialized. Radius is but two-branched in the fore 

 wing, while media is but two branched in both fore and hind 

 wings, vein V_, having coalesced to the tip with V^. In this 

 species the high degree of specialization exhibited \iy C.extorralis 

 has been carried still further, but along a different line. The sep- 

 aration probably occurred below C. agitatellus. The clasps are 

 simply modified from C. agitatellus and for this reason this species 

 is placed in this group. Though the wing is the most specialized, 

 it seems most natural to place the insect next to C. agitatellus, 

 regarding the modifications of the wings as a sidewise develop- 

 ment. 



24. Crambus alboclavellus. The fore wing is almost the same 

 as C. agitatellus, being only slightly narrower. The antennae are 

 a little more specialized, there being a large seta upon the side of 



