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XLVI] portion of its ventral surface, and behind it are two prominent spines. The alimentary canal commences with a short œsophagus, which ends in a proventriculus. A remarkable dorsal diverticulum, corresponding to the food reservoir of the muscid larva, opens into the œsophagus near its anterior end. After the larva has fed, the diverticulum is a very conspicuous object, being seen through the semitransparent body wall as a bright-red area, extending, when full of blood, from the head to about the fifth segment. The midgut is short; the hindgut is long, much coiled, and occupies the greater part of the body cavity. The maggot has a thick integument, which enables it to withstand a good deal of pressure without injury. The duration of the larval period has not been determined. When ready to pupate, the larva selects a suitable spot and lies dormant. The puparium is a dark reddish-brown oblong body, measuring 9-10.5 mm. in length by 4-5 mm. in breadth. The anterior end is roughly conical; the posterior is rounded. The pupa stage lasts from two to three weeks. The fly is usually found sitting motionless amongst the thatch, beams, and cobwebs of the walls and roofs of native huts, but it is very difficult to see on account of its protective colouring, which corresponds exactly with the smoke-stained straw and rafters. It never bites, is usually silent, and deposits its eggs in the dust-filled cracks and crevices of the mud-floors of the huts, particularly in spots where urine has been voided. The larvæ are found especially under the mats on which the natives sleep, in the floor crevices, and in moist soft earth at a depth of 3 in. or more. According to Bentley, as many as fifty could sometimes be found beneath a single mattress. They feed mainly or entirely at night, and they drop off at once if the limb on which they are feeding is moved. Those who sleep on beds or raised platforms are not attacked as a rule unless the bed be low, when the maggot may reach the occupant by crawling 1 up either the supports or the grass wall against which the bed is usually placed. The natives state that the maggot is able to jump to a height of 18 in., but this is unlikely.

In the grass and jungle lands of many tropical and sub-tropical countries land-leeches, probably of special species, often occur in great abundance; so much so that in some circumstances they may prove to be something more than a nuisance. The Hœmadipsa ceylonica is one of the most active, as well as best known, of these. Before feeding, when outstretched, it is about an inch in length and about the thickness of a knitting-needle. It clings to a leaf or twig, awaiting the passing of some animal, on to