1899] 



PtRouse fly. 



61 



shaped organs projecting from the mouth ; antennfe very short, ciliated; 

 eyes large ; ocelli three, on the top of the head. Upper side of thorax 

 depressed ; suture noticeable ; scutellum commonly with hairs only at 

 the hinder edge. Abdomen obconical, hairy, more or less emarginate. 

 Wings longer than the abdomen, of a brownish yellow tint (for neura- 

 tion, see figure, p. 59). Legs hairy, each foot furnished with two 

 claws, and each claw tripartite. By this formation of foot, the Orni- 

 thomyia is easily distinguishable from the more commonly observed 

 Hippobosca equina, in which (see plate) each of the two claws with 

 which each foot is furnished is only two-parted. One of these divisions 

 being (as figured below) large, strong, curved, and pointed at the 



Foot of Hippobosca equina, showing double claws, central process, and long 

 prickly bristle ; also portion of side of claw of H. maciilata, showing parallel grooves 

 and saw-edge— all much magnified. 



extremity ; the other thicker, and much shorter and rounded at the 

 extremity, forming a kind of thumb-like appendage to the chief division 

 of the claws. 



In Ornithomyia (see plate) each foot is similarly furnished with two 

 claws, but each of the claws (see also figure, p. 59) is three-parted. Of 

 the two larger divisions, one is long, narrow, and tapering gradually to 

 the pointed extremity ; another of the divisions is almost as long, but 

 is thicker and almost of the same width throughout to its bluntly 

 rounded tip. The third division, which originates at the enlarged base 

 of the main divisions, may be described as being formed for about half 

 its length of a narrow stem, and then rapidly enlarged to about four 

 times its previous width into a somewhat trumpet-shaped extremity 

 (see plate). 



The subordinate and very elaborate minutiae of the foot apparatus, 

 which, in the main points (though not quite precisely in the size and 

 form of some of the details), correspond with those of the foot of 



