A HISTORY OF ESSEX Colchester LIMNOPHILID^ (continued) Limnophilus fuscicornis, Ramb. Ded- ham Anabolia, Steph. nervosa (Leach) Curt. Colchester Stenophylax, Kol. stellatus, Curt. concentricus, Zett. J Micropterna, Stein. sequax, McLach. Colchester Halesus, Steph. digitatus, Schrank. Colchester Chsetopteryx, Steph. villosa, Fab. Colchester SERICOSTOMATID.S: Sericostoma, Latr. personatum, Spence. Colchester Notidobia, Steph. ciliaris, L. Colchester LEPTOCERID^ Molanna, Curt. LEPTOCERID^; (continued) Molanna angustata, Curt. Colchester Leptocerus, Leach senilis, Burm. "1 cinereus, Curt. J Mystacides, Latr. - lng'cornis, L. } ^^ azurea, L. J HYDROPSYCHID^ Hydropsyche, Pict. instabilis, Curt. angustipennis, Curt. J Polycentropus, Curt. flavo-maculatus, Pict. Colchester Cyrnus, Steph. trimaculatus, Curt. Tinodes, Leach. waeneri, L. R.HYACOPHIUD.ffi Agapetus, Curt. fuscipes, Curt. Colchester Colchester HYMENOPTERA ACULEATA The order Hymenoptera is an extensive one, consisting of insects which as a rule have four membranous wings, though certain among them are wingless. In the Aculeate section, which comprises ants, sand wasps, wasps and bees, the female is provided with a sting, which, being connected with a poison bag, constitutes a formidable weapon of offence or defence. The solitary species consist of fully developed males and females only, but in the social species ants, hive bees and humble bees there are also undeveloped females, known, and very fittingly known, as workers, on whose labour depends the welfare of the community. In recent years, owing principally to the admirable work which has been done in them by Mr. Edward Saunders, these insects have received more attention than was accorded to them formerly, and as a conse- quence their local distribution is much more fully understood and addi- tional species are being frequently added to our list. The late Mr. Frederick Smith, author of A Catalogue of British Bees in the British Museum, occasionally collected at Southend, and more re- cently the Colchester district has been pretty well worked, though it is probable that additional species will for a long time result from further investigation, for while some are excessively local or very erratic in their appearances, others more given to wandering are constantly on the look out for suitable places in which to found fresh colonies ; and seeing that their habitations are constantly liable to adverse influences either by the dense growth of vegetation, the ravages of mankind, or other causes, the Aculeate fauna of a particular district may be materially modified in the course of a few years. Where no locality is given in the list that follows the Colchester district is to be understood, and this includes not only the neighbourhood 98