i;{9 



projecting downwards at an angle ol about 45°. W lien the llj-sliy 

 distal portion is icflcxcd hcncatli the distal vnd ol llic hull), the 

 extremity of llic proboscis has a pointed appearance. Tiie lleshy 

 portion, ^\hieh, like the hull), hears fine hairs, when reflexed ends 

 in the labella, whicli tlierefore come to lie between the pointed tip 

 of the proboscis and the rounded base of the bulb, and, when the 

 proboscis in this condition is seen in profile, look like a fleshy pad 

 lying on the under side of the bulb just beyond the middle. When 

 the proboscis is brought into use, the fleshy portion is extended until 

 it lies more or less in a line with the bulb, and the tubular extension 

 (which, in a fly of normal size, is approximately 0.5 mm. in length) 

 is protruded from between the inner surfaces of the labella, of which 

 it forms a prolongation. The extension is supported internally 

 by a pair of stout, black, chitinous rods, which are visible through 

 the semi-transparent wall, and of which the proximal extremities are 

 situate betAveen the tips of the labella. In dried specimens at any 

 rate, the distal extremity of the tubular extension appears to consist 

 of a thickened fleshy ring, armed with pale yellowish teeth or blades 

 in addition to the circlet of stout, black, pointed teeth, which are 

 situate on its inner margin. As regards other characters of 

 Philcematomyia, it need only be said that the eyes are narrowly 

 separated above in the male and wide apart in the female ; that 

 the hairs on the arista, or bristle-like process projecting from the 

 base of the third joint of the antenna, instead of being confined 

 to the upper side, as in Stomoxys, Lyperosia, and Stygeromyia, 

 are, as shown in fig. I., present on the under side as well, as in 

 Musca domestica ; and that the venation of the wings is approxi- 

 mately the same as in the latter species. 



It will be seen that Philcematomyia forms a remarkable connecting 

 link between the Stomoxys group and the ordinary non-biting 

 Muscidae, in which the broad, fleshy labella at the tip of the proboscis 

 are not adapted for the perforation of the integument of Vertebrates. 

 In the case of Stomoxys and Lyperosia the slender ehitinised proboscis 

 (labium) is thrust bodily into the skin of the animal or human 

 being on which the fly is feeding, and so forms a piercing organ, 

 a hole being first cut in the skin by means of the powerful teeth 



