2G DIPTERA OF NORTH AMERICA. [PART III. 



Ccelometopia seems to be fouuded on Trypeta trimaculata 

 Fab., which Macquart did not identify; it is closely allied to 

 Odonlomera and Setellia. 



Euprosoj)ia undoubtedly belongs to the Ortalidse. 



Notacanthina is founded upon Tetanocera bispinosa Fab. 



The figure of the head of Cruphiocera (better Cryphiocera) 

 seems to indicate that the species would be better placed in some 

 other part of the system, as it has strong bristles on the fore- 

 head ; the other characters, however, prove that its location 

 among the Ortalidse cannot well be called in doubt. 



The position of Plagiocephala among the Ortalidse likewise 

 cannot be doubted ; it seems closely related to Richardia, which 

 also contains broad headed species. 



Campigaster (a frightful compound) is undoubtedly well 

 placed among the Ortalidse, but the name cannot be preserved 

 in its present shape. 



(d.) In Walker. 



Although Macquart's publications do not always define with 

 sufficient precision the systematic position of the genera intro- 

 duced by him, this position could, in most cases, be made out, 

 and moreover, the attempt, on his part, of a systematic distribu- 

 tion is always apparent. Walker's publications on exotic diptera 

 do not, unfortunately, deserve this praise. The systematic de- 

 partment, as well as everything else in them, is treated with the 

 same superficial carelessness. In most cases it would be impos- 

 sible to make out, from his statements, the real place in the 

 system which the genera, introduced by him, must occupy, unless 

 they were accompanied, as is often the case, by the excellent 

 figures of Wcstwood. These usually furnish the necessary data 

 concerning the relationship of the new genera; they would have 

 done so in all cases if Westwood's attention had been directed 

 to the sometimes very minute characters which are used in the 

 classification of the diptera and especially of the Diptera acaly- 

 ptera; the fact that in the majority of cases these characters are 

 reproduced in the figures, give a most brilliant proof of the ac- 

 curacy of Westwood's drawings, and of his keen perception. 



Walker's publications in the List of Dipt. Ins. of the Brit. 3Ius., 

 and in the Insecta Saundersiana, do not raise our expectations 

 very high, as the Ortalidse and Trypetidse are mingled together 



