356 THE BUTTERFLIES OF THE 



color, in shape semi-ellipsoidal, its base flat, and its 

 apex depressed betAveeu the tips of the ribs, which termi- 

 nate exterior to the depression. It is distinctly ribbed 

 with from ten to twelve longitudinal ribs, and connecting 

 the ribs are from thirty to thirty-five transverse striae. 

 Diameter, .031 of an inch ; height, .028 of an inch. 



The larva is unknown. The butterfly may be seen 

 in June. 



New England to Michigan, Illinois, Florida, Colo- 

 rado, Arizona, Washington Territory. 



181. NISONIADES SOMNUS, Lintn. 



Expanse of wings from 1.3 to 1.45 inches. 



Male. Dark brown in color, approaching N. Persius. 

 Fore wings without the anteapical white spots above, 

 and the large patch of bluish- white scales resting on the 

 discal cross-vein of N. Icelus. The black transverse 

 bands have the position and character of those of N. 

 Icelus, but are almost lost in the ground color. Hind 

 wings nearly as dark as the fore wings, showing indis- 

 tinctly the two rows of pale brown spots. 



Under side of wings bronze by reflection. The fore 

 wings have a short costo-apical white streak in cell 8, or 

 between the third and fourth subcostal venules, and a 

 minute white dot above this, or in cell 9 (N. Icelus 

 usually has a subquadrangular white spot in the upper 

 interspace beyond the cell and the two lower subcostal 

 interspaces, and occasionally the spots form a continuous 

 line nearly across the wing from the lower median inter- 

 space to next the lower subcostal interspace). There is 

 an intervenular series of pale streaks, and on the hind 

 wings the two rows of yellow-brown spots are indistinct. 



