294 Hominoxious Arthropods 



ii. Proboscis extending beyond the palpi. 



j. Wing with cell MS closed. Tropic America 



( = Diclisa) Scione Wlk. 



jj. Cell MS open; ocelli present or absent. Two or three 



eastern species; many south and west. .Pangonia Rdi. 



ff. Third segment of the antenna with five divisions; ocelli present. 



g. First and second segments of the antenna short, the second only 



half as long as the first, three western species Silvius Rdi. 



gg. First and second segments of the antenna long, the second 

 distinctly over half as long as the first. Deer flies. Many 



species, widely distributed Chrysops Meig. 



ee. Hind tibia without spurs; ocelli absent. 



f . Third segment of antenna with four divisions, no tooth or angula- 

 tion; wings marked with rings and circles of darker coloring; 

 front of the female very wide. Widely distributed. H. ameri- 



cana, H. punctulata Haematopota Meig. 



ff. Third segment of the antenna with five divisions (fig. i6ib). 

 g. Third segment of the antenna not furnished with a tooth or 



distinct angular projection. 



h. Body covered with metallic scales; front of female of normal 

 width; front and middle tibiae greatly dilated. L. 



lepidota Lepidoselaga Macq. 



hh. Body without metallic scales; antennae not very long, the 

 third segment not cylindrical, not situated on a projecting 

 tubercle; front of the female narrow. South. D. 



ferrugatus ( =Didbasis) Diachlorus 0. S. 



gg. Third segment of the antenna furnished with a tooth or a 



distinct angular projection, 

 h. Hind tibiae ciliate with long hairs. S. W. and tropics. 



Snowiella and Stibasoma. 



hh. Hind tibiae not ciliate. 



i. Species of slender build, usually with a banded thorax and 

 abdomen; third segment of the antenna slender, the 

 basal prominence long; wings mostly with brownish 



markings. Tropic America Dichelacera Macq. 



ii. Species of a stouter build; third segment of the antenna 

 stout, its basal process short (fig. i6ib). Many species, 



widely distributed Tabanus L. 



dd. With another group of characters. 



e. Squamae small, antennae variable, thinly pilose or nearly bare species, 

 without distinct bristles; wing veins not crowded anteriorly, R4 and 

 RS both present, basal cells targe; middle tibiae at least with spurs 



LEPTID^E 



f. Flagellum of the antenna more or less elongated, composed of 



numerous more or less distinct divisions 



XYLOPHAGIN.E and ARTHROCERATIN^E. 



ff. Antennae short, third segment simple, with arista or style; face 

 small, proboscis short 



