A HISTORY OF ESSEX custom hitherto to impale these insects on long pins without making any attempt to arrange and display their wings, bodies and legs, and treated in this fashion they are certainly melancholy and pitiable objects ; but a collection in which the specimens are all properly set and arranged is far more useful for all purely scientific purposes, and is calculated to form a source of considerable pleasure to those who are not wholly wanting in all aesthetic sensibility. Some of the families into which this order is divided require much attention and revision before even the most competent British entomo- logists can speak with authority about them ; and seeing how small a portion of our own county has been even superficially investigated, it behoves us to be modest in displaying our knowledge even of the better understood families, but a little should be said about some of them. The Gall Gnats (Cecidomyidce and their allies) have been fully dealt with by Mr. Fitch, and to his article on the ' Galls of Essex ' (Trans. Essex Field Club, ii. 98-156) reference should be made by any one desiring the best available information concerning them. The Bibionidce are represented by about a dozen of the typical genus Bibio. B. venosus, the scarcest of these, is occasionally found at Colchester; B. marci (St. Mark's fly) is a conspicuous black insect which suddenly appears in vast swarms early in the spring, and is one of several insects for the ' bringing over ' of which the rural population make the east wind responsible. The Gnats (Culicida, etc.) are well in evidence in mild weather throughout the year. Several of them are only too well known from their blood sucking propensities, and in certain parts of the county species are found which if met with elsewhere would be called mosqui- toes, and would have as good a right to the name as other members of the same family to which it appears to be somewhat indiscriminately applied. The Crane-flies (Tipulida:}, more familiarly known as 'Daddy-long- legs,' are numerous, and some of them, such as Tipula gigantea, T", lutes- cens, etc., are large and handsome insects ; but their legs are so loosely joined to their bodies that it is extremely difficult to prepare them for the cabinet in perfect condition, and therefore they do not receive the attention from collectors which they otherwise deserve. Among the better species Dictenidia bimaculata occurs at Colchester, and the hand- some Ctenophora flaveolata has been captured by Mr. G. F. Mathew at Dovercourt. The Stratiomyida include some fine insects, notably Stratiomys pota- mida, S. longicornis and Odontomyia ornata, which are occasionally found at Colchester, and S. furcata and O. tigrina, which occur on the coast. The species of Sargus and Chloromyia are elegant insects with brilliant green and purple metallic bodies ; they are well distributed and not un- common. The Tabanidce or Breeze-flies, also known as Gadflies, which are so troublesome to horses and cattle and occasionally to mankind, are natur- 178
