50 DIPTERA OF NORTH AMERICA. 



of several of them, and retained the genera Anomoia and Euleia, 

 which he had previously founded himself; besides, he erroneously 

 brought again among. the Trypetidce the genus Camptoneura, which 

 Macquart had formed on Trypeta picta Wied., and correctly placed 

 among the Ortalidce. 



The most recent attempt at a detailed classification of the Eu- 

 ropean species of the old genus Trypeta is that given by Rondani 

 in his "Prodromus Dipterologice italicce." He retains though in 

 a much altered sense the genera of R. Desvoidy : Oxyna, Uro- 

 phora, Rivellia, Tephritis, Acinia, Aciura, Terellia, and Orellia, 

 and adopting the genus Ceratitis M. Leay and Myopites Breb. , he 

 creates the following new genera: Goniylossum, Carpomyia, Cera- 

 jocera, Chetostoma, Epidesmia, Myoleja, Spathulina, Dithryca, and 

 Oplocheta. But these genera are less fit for reuniting what is 

 really allied, than for isolating out of their nearest relationship 

 such species as are distinguished by any specific peculiarity and for 

 crowding them inordinately together. The dichotomic division of 

 genera from single characters without any indication of the true 

 generic distinctions, renders it impossible to refer to them the 

 other species described by authors, and it is not at all sufficient 

 for this purpose to name a typical species, especially as some of 

 these typical species have not yet been described, and the correct- 

 ness of the names of the others is not proved. Moreover, the 

 characters ascribed by Rondani to the single genera are not all 

 quite certain, and some of them, for instance the scutellum of 

 Myoleja, which is said to have two bristles, the scutellum of Cera- 

 titis six bristles, appear to be errors of the observer. 



If we add to what we have said already that the genera Xar- 

 nuta, Themara, Calantra, and Aragara, erected by Walker in the 

 "Proceedings of the Linnsean Society," with some probability 

 belong here, and that perhaps the genus Dasyneura Saund., and 

 Rachiptera and Elaphromyia Bigot are Trypetidce, both the va- 

 riety of the forms belonging to the genus Trypeta Meig. and a 

 picture of the chaotic state into which their arrangement has been 

 thrown will be sufficiently illustrated. 



The genus Dacus, restricted by Meigen to the Dacus Olea> 

 Fabr. (the renowned blight of the olive) and used by Wiedemann 

 in a wider sense, is nearest related to the genus Trypeta Meig. ; 

 Fabricius, who formed this genus, comprises so different species 

 in it that we may scarcely consider it as a creation of his. How- 



