THE NESSUS MOTH. 



635 



in some lights, and the upper pair are traversed by numerous 

 wavy bands of black. The lower wings are nearly plain, but 

 along their upper margin runs a broad stripe of bright yellow, 

 which is very visible when the wings are spread. There are 

 many species of this genus ; one of the most remarkable is 

 Thyreus Nessus, also of New York. This insect is smaller in 

 size, has the abdomen banded with white, and the yellow streak 



Fig. 370.— Tliyreus Abbati. 

 (Olive-brown, with a yellow streak.) 



is replaced by one of blood-red, to which the insect owes its 

 specific name. The classical reader will scarcely need to be 

 reminded that the centaur Nessus was pierced to the heart by 

 the arrow of Hercules, and that his flowing blood is fancifully 

 supposed to be represented by the crimson streak of the lower 

 wings. The generic name Thyreus is Greek, signifying "a 

 shield," and is probably given to the insects in allusion to their 

 shape when their wings are closed. 



The genus Deilephila is well known to English entomologists 

 on account of the rare and valuable Spurge Hawk Moth, which 



