206 STUDIES IN THE GENUS THANAOS 



evidence of two species on account of the difficulty of differentia- 

 tion and the probabiUty of misidentification. The difference in the 

 recorded food plants may mean much or it may mean nothing as 

 butterflies have a number of food plants. Further studies of the 

 life histories appear necessary to establish specific identity. The 

 only tangible differences I can find to separate them are first — ■ 

 lucilius is smaller; second — If a line be drawn from the costal vitre- 

 ous spots to the inner margin it will divide a fighter colored area. 

 On the inner side this gives the appearance of a lighter spot which is 

 absent or faintly indicated in persius. 



The question of broods is not settled as there are late records for 

 persius. The vitreous spots vary alike in each and give no help. 

 There may be none, one or two, below the costal spots, in both 

 lucilius and persius. I have not been able to discover any tangible 

 differences in the genitalia of the two and must conclude that the 

 question as to whether we have to deal with a single species and a 

 variety, or with two species, is still in doubt. 



var. afranius Lintner, Thirtieth Report N.Y. State Cabinet of Nat. Hist., 



175, 1878 (Ent. Contributions No. 4, p. 63, 1878). 

 Elrod, Butterflies Montana, p. 150, fig. 110. 

 Biologia Centrali-Americana, Lepid., ii, 459, tab. 91, figs. 24, 25, 26. 



"Thorax and abdomen above, black; beneath, with brown hairs. Palpi 

 clothed with long brown hairs. Legs fuscous. Prirnaries with the costal 

 margin nearly as straight as in A'', persius, but rounded toward the apex; 

 moderately bent basally. Outer margin more rounded than in any male 

 Nisoniadcs known to me (the females, as a rule, having more rounded wings), 

 as much so as in A'', brizo female. Inner angle rounded, with internal margin 

 short. Theiisual black markings in the basal region of the wing; the re- 

 mainder clouded with brown, distinctly relieving the transverse line of 

 elongated black spots and the row of rounded submarginal black spots; a few 

 gray scales are sprinkled over the brown ground. The black spots of the 

 transverse band above vein two are more elongated in proportion to their 

 width, more acute toward the outer margin, and more sharply defined than 

 in any other species — even than in A'", ausonius. The line of four small, 

 anteapical, white, hyaline spots is sensibly drawn inward toward the base, so 

 that an imaginary line traversing these spots will cut the outer margin 

 within its apical half. A white hyaline spot rests on the black spot in cell 

 three, and the three black spots in cells two and one b, have some grey 

 scales centrally. There is a trace of a small whitish, hyaline, discal spot. 

 The terminal margin is without the black line seen in N. marlialis. Secon- 

 daries, dark umber-brown with the two rows of brown spots, similar to those 

 in A'^. persius female. Wings beneath, a rich umber-brown, showing on the 

 primaries the discal and anteapical spots more plainly above, and a white 



