MODIFICATIONS OF STRUCTURE. 373 



more beautiful than the upper pair, as is often the case with 

 insects. The base of the wing is deep shining purple, followed 

 by a broad wavy band of yellow. The rest of the wing is pale 

 brown, except a nearly circular spot of yellow near the tip. If 

 the wings be viewed on the under surface, they will be seen to 

 be very glossy and iridescent, with a decided purple gloss 

 extending over the whole wing. There is some variation in 

 the size and shape of the spots, but the general appearance is 

 the same in all specimens. 



There are many species of this very remarkable genus, 

 extending over a considerable portion of the world ; being 

 found in Europe, Asia, the West Indies, and Africa. One of 

 them, called appropriately Ascalaphus filipennis, a native of 

 India, has the lower wings even more narrowed than those of 

 the preceding species. The wings, in fact, are reduced to a pair 

 of delicate thread-like appendages, which have not the least 

 appearance of being wings. Were they removed from the insect 

 they might readily be taken for a pair of long and slender 

 antennas, and, as they trail behind the body, they look very 

 much like legs. Indeed, as the insect is a very small one, it 

 bears a most curious resemblance to a gnat, the thread-like 

 wings imitating the hinder legs. 



Why the name of Ascalaphus was given to this genus of insects 

 I cannot imagine. It is a name which was given by Aristotle 

 in his " History of Animals " to some bird which is thought to 

 be an owl, and is therefore singularly inappropriate as a name 

 for an insect. 



We now come to another family of Neuroptera ; namely, the 

 Sialidse. We have several species of Sialidse inhabiting England. 

 They always frequent the neighbourhood of water, and may be 

 seen in numbers clinging to the trees or foliage near the water- 

 side. They are brown in colour, and are generally mistaken for 

 moths by non-entomologists. Anglers always welcome them, as 

 the fat-bodied female Sialis forms an excellent bait for various 

 fish, the trout being specially fond of them. 



If placed in the water, these insects swim wonderfully well, 

 closing their wings and scuttling along at a great pace, leaving 

 quite a long wake behind them. In my boyish days, moth- 



