1918] Crambince of North America 57 



Systematic Position. In its relationships this species Has 

 between C. trisectus and C. mutabilis, more closely allied to the 

 latter. The moth resembles that of mutabilis in the dark 

 shading on the costa proximad, the dentate subterminal line 

 and the whitish veins in the middle of the forewing. It is, 

 however, more richly colored than that species and especially 

 do the yellow stripes in the posterior half of the primaries 

 contrast with the much less lively coloration of mutabilis. 

 Structurally its close approach to mutabilis is shown in the 

 narrow forewing, the broadly pectinate male antennae, the naked 

 spine-like harpe (Fig. 10) and the hooked uncus (Fig. 6). It 

 differs in that the male antennal processes (Fig. 3) are less 

 abundantly supplied with sensoria, the scaphium is longer, the 

 valve is both longer and somewhat wider and the harpe while 

 spine-like is large, doubly curved and long, exceeding the 

 valve. This latter character in itself is sufficient to define the 

 species for in mutabilis the harpe is a slender spine not more 

 than half the length of the valve and in trisectus, the nearest 

 form on the other side, the harpe is falcate and setigerous and 

 in length about equals the valve. The relationship to mutabilis 

 is shown also by the larvae for the markings of the two are very 

 similar differing only in shade, brick-red for hemiochrellus and 

 dull brown for mutabilis. During their incubation period the 

 eggs of the two species assume very nearly the same shade, a 

 pale salmon-yellow. 



Descriptions. Adult: The description of the adult moth 

 as given by Fernald (1896) is very accurate and complete and 

 is here quoted with the addition of a description of the genitalia 

 by the writer. 



Expanse of wings, 22 mm. Head and thorax pale ochre-yellow; 

 palpi thickly sprinkled with grey atoms. Fore wings bright ochre- 

 yellow between the white median vein and hind margin with dusty 

 stripes, and usually with a clear yellow stripe along the fold; costal 

 portion yellowish-gray, darker toward the base; median line fine, 

 rust-brown, forming an acute angle at the end of the cell, and extending 

 in a nearly straight line to the middle of the hind margin; subterminal 

 line fine, dark brown, dentate on the veins and parallel with the outer 

 margin except at the costal end, where it curves sharply inward and 

 terminates at the outer fourth of the costa ; terminal space dusty-gray ; 

 terminal line rather indistinct, upon which in some specimens, may be 

 seen seven very fine dark gray dots; fringes light gray. Hind wings 

 light gray; fringes lighter. 



