LACE-WINGED FLIES. 99 



In the first sub-family, the Sialince, the head is transverse, the 

 prothorax broad, and of moderate length, and the larva is aquatic. 

 The best known British species is Sialis Lutarius, Linn., a very abun- 

 dant insect near water. It is smoky black, with numerous nervures, 

 and measures nearly an inch and a half across the wings. Several 

 very large insects belonging to this family are common in North 

 America. One of these is Conjdalis Cornuta, Linn., which measures 

 five and a half inches across its greyish semi-transparent wings. 

 It is quite harmless, though the huge mandibles of the male give 

 it a very formidable appearance. 



In the Haphidiince the head is long ; the prothorax is long and 

 slender, tapering in front ; and the larvae live under bark. Several 

 dark-brown species, measuring about an inch across the wings, are 

 common in Europe, to one of which Linn6 gave the name of 

 Raphidia Ophiopsis, from a fancied resemblance of the long neck 

 and head to that of a snake. 



Family IT. — HemeroUidce. 



Wings strongly deflexed ; hind wings not produced at the anal 

 angle ; body usually slender ; larva not aquatic. 



The first sub-family, the Mijrmeleonincc, includes the Ant- 

 Lions. Their larvifi are yieW known to form a pitfall of loose 

 sand, at the bottom of which they lurk, with only their jaws pro- 

 jecting, and feed on the insects which may happen to fall over the 

 edge. They are not found in Britain, but the larva of our common 

 Green Tiger Beetle has similar habits, and might be called the 

 British Ant-Lion. Two brown species, which expand about two 

 inches [Myrmeleon Formicarius, Linn., and M. Formicalynx, Burm.), are 

 not uncommon on the Continent. They resemble dragon-flies, 

 but their bodies are shorter and less tapering, and they may be 

 immediately distinguished by their short, clubbed antennae. The 

 genus Palpares, Eamb., is found throughout Asia, Africa, and South 

 Europe, and includes species of moderate or large size, with semi- 

 transparent white or yellowish wings, banded or spotted with brown 

 or black. F. Libelluloides, Linn., is found in South Europe and the 

 Mediterranean region. 



The Ascalaphince form another sub-family not represented in 

 Britain. They may be distinguished from the Ant-Lions by their 

 long clubbed antennae, and their shorter and broader wings and 

 bodies. Several species of the genus Ascalaphus, Fabr., with trans- 

 parent wings, variously ornamented with brown and yellow, are 



