ANTENNAE 



441 



peculiar to the Order, viz. three segments, the outer one of 

 which is of diverse form, according to the genus or species, and 

 bears on its front a fine projecting bristle, frequently feathered, 

 as in Fig. 213, F ; and often distinctly divided into two or more 

 joints. This form of antenna is found in the series Aschiza and 

 Schizophora ; it is well exemplified in the common house-fly, where 

 the organs in question hang from the forehead, and are placed in 

 a hollow formed for their reception on the front of the head. 

 Flies with this form of antennae are called Athericerous. Between 

 the two forms of antennae we have mentioned there exists what 

 may, speaking roughly, be called an intermediate condition, or 



B 



FIG. 213. Antennae of flies. A, The two antennae of Glaphyroptera picta (Myceto- 

 philulae) ; B, antenna of ffexatoma pellucens (Tabanidae) ; C, of Asiltis crabroniformis 

 (Asilidae) ; D, of Leptis scolopacea (Leptidae) ; E, of Dolichopus undulatus (Doli- 

 chopidae) ; F, of Volucella bombylaiis (Syrphidae). (After Waiidolleck.) 



rather a variety of intermediate conditions, associated in the 

 series Brachycera (Fig. 213, B to D). 1 Here there are three 

 (sometimes one or two) segments and a terminal appendage, 

 but the appendage is usually compound (often so distinctly com- 

 pound that it is evidently a series of partially, or even completely, 

 separate joints, Fig. 213, B) : the appendage in these cases is ter- 

 minal, that is to say it is placed, not as in the Eumyiidae on the 

 front of the joint that bears it, but (in the great majority of 

 Brachycera) at the tip thereof; this appendage is often conical 

 and pointed, often hair-like. Exceptional forms of antenna are 

 found in the parasitic flies of the series Pupipara. In the Order 

 generally the two basal joints of the antennae are evidently 

 distinct in function from the others, and form the " scape " ; the 



1 It may be well to remark that this name was formerly applied to all Diptera 

 except Nemocera. 



