12 DIPTERA OF NORTH AMERICA. [PART III. 



prseapical bristle ceases to be an undoubted distinctive character 

 of the Ortaiidse. That these two species, to which several un- 

 described South American forms have to be added, are to form 

 the nucleus of a new genus is beyond question. I propose for 

 it the name of Automola. 



Whether the two species of Fabricius, which Wiedemann 

 quotes among the species of Ulidia, really belong to this genus' 

 cannot be decided without seeing the original specimens ; but I 

 have no doubt that they belong to the Ortaiidse. I would sup- 

 pose that Ulidia stigma belonged to the genus Notogramma, and 

 that Ulidia senea is a Chrysomyza. 



Wiedemann's genus Pyrgota, with which Oxycephala, Macq. 

 is absolutely identical, shows all the characters of the Ortaiidse, 

 It is closely allied to Adapsilia, the only difference being that 

 the antennal foveae are shorter, while in Adapsilia they are 

 parallel, and run down to the edge of the mouth ; but, as in dif- 

 ferent species of Pyrgota these foveae vary in length, this differ- 

 ence has so little importance that Adapsilia might, without any 

 inconvenience, be united with Pyrgota. 



The genus Dacus, in Wiedemann's writings, is a mixture of 

 many very different forms of diptera, most of which are Orta- 

 iidse and two species are Trypetidse. Two of the species of 

 which Wiedemann formed the first section of the genus Dacus, 

 form now, together with other species added since, the genus 

 Stenopterina, which Macquart established under the name of 

 Senopterina, and which he placed quite correctly among the 

 Ortaiidse. The Dacus jlavicornis, placed by Wiedemann in the 

 first division as a third species, has a certain general resemblance 

 to the two former species ; it differs, however, in the bareness of 

 the first longitudinal vein and in several other characters, too 

 much to be united in the same genus with them ; nevertheless, 

 this species, as well as the two others, belong to the Ortaiidse. 

 Among the species of Wiedemann's second division of Dacus 

 D. succinctus must be referred to the Ortaiidse; it belongs in 

 the immediate relationship of 0. syngenesise. Dacus bicolor 

 likewise belongs to the Ortaiidse. The remaining Dacus of 

 Wiedemann's second division are Trypetidse; some of them 

 belong to the genus Trypeta, if we take it in the wider sense of 

 Meigen and Wiedemann ; for instance, Dacus parallelus, fra- 



