356 . CONOPIDiE. 



irregularly and suddenly towards the base. Secondary but 

 fairly constant characters are : the greater narrowness of the basal 

 part of the abdomen, especially of the 2iid and 3rd segments, 

 which are often considerably elongated and cause the abdomen 

 to resemble that of a wasp ; the proportionately greater length of 

 the 2nd autennal joint, which is often much longer than the 1st 

 and 3rd together ; and the position of the anterior cross-vein, 

 which is nearly always placed well beyond the middle of the discal 

 cell. All the other features are plastic, and vary in different 

 species independently of one another. Conops sepulcliralis and 

 Physocepliala mvnda are species more or less intermediate between 

 the two genera. 



Range. Practically world-wide. 



Life-Mstori/ : see under heading of family, p. 342. 



Turning to the differentiation of species, this genus has offered 

 as many difficulties as have been encountered in any case dealt 

 with in the present volume. Owing to the variability of every 

 available character, except perhaps that of the inci*assation of the 

 hind femora, it has been impossible, even with all the species 

 before me at once, to frame any table of species that would cover 

 all the individual forms. Wide allowances must therefore be 

 made on these grounds : and the identification of a single 

 specimen of any one of the closely-allied sjDecies is often quite 

 impracticable, even to anyone fairly conversant with the genus, 

 unless authoritatively named specimens in good condition are 

 available for comparison. 



Table of S2iecies. 



1. Wing with dark band extending to tip of 



3rd vein, even if fainter or nearly absent 



just before its end 2. 



Wing with dark band ending at tip of 2nd 

 vein or at a short distance beyond it, 

 always at some distance from tip of 3rd 

 vein 7. 



2. First basal cell brown ; basal half of 1st 



posterior cell brown ; discal cell with its 

 base and part of its front and hind sides, 



brown 3. 



First basal cell clear; basal half of 1st pos- 

 terior cell brown ; (discal cell may be 

 slightly suffused at base) 6. 



3. Hind femora always with a broad black 



band hicolor, sp. n., p. 357. 



All femora wholly orange 4. [p. 358^ 



4. Discal cell wholly brown uurantiaca, sp. n., 



Discal cell clear 5. 



5. Third abdominal segment entirely orange- 



brown (at most the extreme hind margin [p. 359., 



is blackish) nigrofasciata, Brun., 



Third abdominal segment about eqnally 

 divided into red-brown, black, and gold- 

 dusted portions riifescens, sp. n., p. 3G0. 



