160 Twenty- SIXTH Report on the State Museum. 



primaries, the pale subcostal nervure with brown linings, and in the 

 form, color and marking of its orbicular. In size and in the dark 

 coloring of its secondaries it is nearer to herilis. 



It is readily distinguished from siibgothica by its smoky-brown 

 secondaries, broadly dark outwardly and paling gradually inwardly, 

 in marked contrast with the distinctly brown-bordered white wings 

 of that species, especially in the $> . It has not the red reniform of 

 suhgothica. 



Its most prominent differential features, compared with A. herilis, 

 are the following: While the antennal structure is the same in the 

 three species, in this the pectinations are stronger than in herilis. 

 Both the subcostal and median nervures are pale gray, bordered with 

 brown lines. The orbicular is concolorous with these nervures, more 

 broadly open above, almost or completely uniting superiorly with 

 the reniform, and with an interior brown line forming nearly a tri- 

 angle, in continuation of the two lines bordering the subcostal; in 

 herilis the orbicular is less open, approaching a IT, and in some 

 instances contracted above into a suborbicular form, and separated 

 by some space from the reniform. It also differs from herilis in the 

 acute extension of the internal tooth of the anterior median line, con- 

 necting with or nearly approaching the posterior median ; in the 

 interspaceal forked black rays behind the cell and between the median 

 nervules ; in the greater distance of the posterior median line from 

 the reniform ; in its less distinctly marked posterior median line (in 

 herilis usually continuous and composed of interspaceal crescents) ; in 

 its paler subterminal region ; in its better defined subterminal line 

 preceded by sagittate spots ; in the distinct marginal black crescents 

 interspaceally ; in its paler costal region and general dark brown 

 shade of the wing, instead of blackish ; in its paler tegulae, and collar 

 less prominently marked with a transverse black line. 



Material under examination in the above comparisons; A. suh- 

 gothica, IT 6 's, 12 ? 's ; A. tricosa, 9 ^ 's, 5 $ 's ; A. herilis, 14 $, 's, 



5 ? 's. 



Measurements of the expanse of wings of the three species give 

 the following results : 



Average. Min. Max. 



A. subgothica 10 spec. 1.55 in. 1.37 in. 1.62 in. 



A. tricosa 9 " 1.70 1.61 1.81 



A. herilis 14 " 1.60 1.37 1.69 



