STTLOGASTER. 371 



llnnge. "Witli the exception of the new species described 

 here from India, and of two or three African species, the few 

 known representatives of this peculiar genus are confined to the 

 Americas. 



Life-histonj not worked out, but it is thought that these 

 insects are parasitic on ants. Bates, in ' The Naturalist on the 

 Amazons ' (end of chapter xii) states that these flies follow ants of 

 the genus Eciton in small swarms, probably for the purpose of 

 depositing their eggs in the food which the ants are carrying 

 into their nest, in which place the Stylogaster would thus be bred. 

 Professor W. M, Wheeler has, however, little doubt that tlie flies 

 are entoparasites in the bodies of the adult ants, not of their 

 prey : see ' Ants' (New York, 1910), pp. 261, 419. 



AVilliston makes this genus the type of a separate subfamily, 

 but the only important differences between it and other Mtopin^ 

 consist in the shortness of the anal cell, the narrowness of the 



Fig. 70. — Stylogaster orientalis, sp. no v., prulile of head. 



frons in the S -, and the great length of the ovipositor in the $ . 

 Though Macquart both described and figured the anal cell as 

 elongate, this must have been an error on his part. The 

 question as to the e.xact identity of the species stglata, Fabr., on 

 which he founded his genus need not be discussed here, but it 

 may be observed that thougli Roeder is of tlie opposite opiin'on, 

 Williston considers its exact determination to be now impossible. 

 Williston also claims that Wiedemann, in redescribing stglata, had 

 really two speries before him and only females of each, instead of 

 both sexes of stglata. Other species from North America referred 

 to Stglogaster have the anal cell extremely small, and I. have not 

 been able to trace a single species in which it is long. West- 

 wood's genus (Stglomgia) was stated to differ from Macipiart'H 

 mainly in the very small anal cell, but the two may now be con- 

 sidered absolutely synonymous, it being impossible to avoid the 

 conclusion that Maccjuart was in error as regards this cell. 

 Williston states that the subcostal cross-vein (though he does not 



