14 



with the abdomen, is of a darivish brown. A remarkable straight narrow hne, or bar, of a cream colour, 

 arises from the middle of the anterior edge of each of the fore wings, and, crossing both anterior and 

 posterior wings, ends at the abdominal edges, about half an inch below the abdomen ; so that, when the 

 wings are extended, as in the figure, these lines, with the anterior edges, form an equilateral triangle. 

 The space within the triangle is dark brown ; but the parts, near the shoulders, are lighter, ha\'ing a 

 greyish cast or hue, and contain many small transverse curved streaks, extending to the anterior edges, 

 where they are large, black, and very conspicuous, like stripes. Some transverse markings of this kind, 

 are dispersed on the posterior edges of the superior wings, and also on the abdominal edges of the pos- 

 terior. On the outside the triangle, both on the anterior and posterior wings, is a fascia, of light brown, 

 about half an inch broad, which deepens into a dark brown. On the posterior wings, after becoming 

 dark, it softens again into the same light colour, continuing to the external edges. Each of these wings 

 is ornamented with two tails, the inner ones the longest and near an inch in length, the tips of 

 which incline towards each other ; the lesser or outer tails, are about half an inch long, strengthened 

 by the tendons of the wings passing through the middle of them ; all of them being bordered with a soft 

 ray of dark brown. 



Under Side. The bars or lines, which form the triangle on the upper side, are not visible on this ; 

 but the inclosed triangular field appears of a light greyish brown, darker at the borders, and thickly 

 beset with small brown streaks, parallel to each other, and surrounding the body. The costal nerve of 

 the anterior wings composes an edging in each, about an eighth of an inch broad, which diminishes as it 

 approaches the external angle, white, and beautifully marked with black streaks, but smaller than those 

 seen on the upper side. Outside the triangle, both in the anterior and posterior wings, is a broad 

 border of white, which softens into a browii, but lighter than that on the upper side. Both hi the white, 

 and in the brown, are some small dashes of black, very thinly dispersed. Tlie internal margin of the 

 posterior wings is furnished with a deep fringe, and the black marks situated below the abdomen, are larger 

 and broader than those on the upper side. The tails are whitish, bordered with brown, and appear as 

 on the upper side. 



This is one of those anomalous forms, whereof examples occur in every tribe of animals, 

 bafflmg the skill of the most profound systematists. By Linnseus, and many other authors, 

 it was considered as a butterfly, and certainly the genus Urania (in which it is placed by 

 Latreille), as we learn from Mr. W. S. MacLea}''s valuable memoir upon that genus, pub- 

 lished in the first volume of the Transactions of the Zoological Society of London, is com- 

 posed of day-flying species. Fabricius, however, regarded it as a moth, belonging to the 

 genus Noctua, and nearly related to the genus Erebus, of which the Erebus Odora, figured 

 ni the third plate of the present volume, is a conspicuous species; and when we examine 

 the structure of the palpi, and the spurs upon the posterior tibiae, we find good reason for 

 adopting this relation, admitting, at the same time, that the group in question is one 

 which, fi-om its various afiinities and analogies, it is very difficult to assign to any single 

 section. 



