54 Memoirs of the Indian Museum. [Voi^. Ill, 



reduced. This is called "complete chaetotaxy " and consists of two 

 pairs of scapular, a pair of dorso-central, a pair of prae-scutellar, one 

 humeral, two noto-pleural, one prae-sutural, three supra-alar, one or two 

 mesopleural, one pteropleural and one sternopleural. Very characteristic 

 are the four bristles (scapular) in front of the thorax. 



3. The legs without praeapical bristle on the tibiae and with spurs only at the 



end of middle tibiae. 



4. The abdomen with four segments in the male and with five in the female, 



the first segment being very long and composed of two segments soldered 

 together. Abdomen of the female terminating in a corneous, three- 

 jointed and pointed ovipositor, often very long and usually flattened. 



5. The wings have a characteristic neuration and are usually marked with a 



distinct pattern, consisting chiefly of bands or reticulate patterns. The 

 auxiliary vein becomes indistinct towards the end, where it is merged in 

 the stigmal callosity ; the first longitudinal vein is usually beset with 

 spines, the third also in many cases; the basal cells are of large size; the 

 anal cell likewise large, with its lower angle mostly drawn out into a 

 point which in some cases is very long. 



If attention is given to the assemblage of these characters, it is impossible to 

 confound a Trypaneid with another acalyptrate Muscid with similarly patterned 

 wings. 



There are two closely related families^, in both of which the females possess a 

 similar corneous ovipositor, the Ortalidae and the Lonchaeidae ; the first have also, 

 as a rule, variegated wings and are therefore very often mistaken for Trypaneids. 

 But the Ortalids have no lower fronto-orbital bristles, and the auxiliary vein is 

 distinct as far as its end in the costal vein. Both these characters are also to be 

 found in the lyonchaeids, which have also the basal cells of much smaller size. 

 There are in addition some Agromyzids with a corneous ovipositor [Liriomyza) , but 

 these flies are sharply distinguished by the simple flrst vein, by the presence of 

 vibrissae, and by the wings not being blunt. 



The Oriental fauna is rich in I^auxaniids which show a wing-pattern very like 

 that of Tephritis {Sapromyza trypetoptera, pulchripennis , etc., Amphicyphus reticu- 

 latus) ; but these forms are easily distinguished by the crossed post-vertical bristles, 

 the very small basal cells and the want of the corneous ovipositor. 



The Heleomyzidae, some of which have been mixed up by Walker, are readily 

 distinguished by the spinose costa and by the strong bristles (vibrissae) at the edges 

 of the mouth ; the Heteroneuridae are distinguished in the same way and also, more- 

 over, by the very approximate cross veins. The Sciomyzidae and Dryomyzidae are 

 distinguished by the presence of a praeapical bristle on the tibiae. Finally the 

 Ephydridae and Drosophilidae have no distinct auxiliary vein, and the second basal 

 cell is usually fused with the discoidal. 



^ Not speaking of the Tachiniscidae, which so far as is known are exclusively Neotropical. 



