to6 K^ANSAS U^fIVERSITY QUARtE^LV. 



There is yet another point of resemblance between Rhaphiomidas 

 and Triclonus which appears to me to be a very remarkable coinci- 

 dence, if we assume the forms to be unrelated. In his original 

 description of the former genus Osten Sacken refers to a singular and 

 remarkable metapleural process situated in front of the halteres, which 

 he could not understand: "In front of the halteres there is a singular 

 conical body, a little shorter than the halteres, the homology of which 

 I do not attempt to explain." Precisely the same process ocQMx?,'va. 

 Triclonus, as my specimens show, and as Thomson described and 

 figured in Harmophana {Triclonus^. 



Taking all these facts into consideration, is it not rather forced to 

 assume that the relationship to a form like Triclo?ius, possessing 

 almost identical neuration, mouth-parts, metapleural process and 

 habits, is less intimate than to the Asilidse, where the neuration is 

 very different, the mouth-parts and habits are entirely dissimilar, and 

 the trichostical bristles replace the metapleural process, because the 

 antennae, ocelli and thoracic bristles agree! 



Brauer is of the opinion that Triclo?ius is not a true Mydaid 

 (2). With this view I cannot agree. But, even should we ac- 

 cept it as distinct from this family, it would weaken rather than 

 strengthen Osten Sacken's position, for it is an eremochaetous form, 

 and could not by any possibility be placed among the Asilidse. 



However, leaving Triclonus and Rhaphiomidas entirely out of 

 account, there remain arguments against the union of Apiocera and 

 the Asilidse which seem to me insuperable. In the first place, the 

 Asilidse are pre-eminently a family of predaceous insects; not a spe- 

 cies is known but what feeds upon the juices of insects. Apiocera is 

 a flower-fly, as the mouth-parts, the legs,and Coquillett's observations 

 show. This difference in habits might be overlooked in the presence 

 of striking resemblances, as Osten Sacken justly says. But, aside 

 from what has already been spoken of, there are fundamental differ- 

 ences in the structure of the mouth-parts, indicating a remote genetic 

 identity of the two groups. I do not mean the differences as seen in 

 the labella alone ; Brauer and Mik have both used this argument with 

 force. By referring to the figures and descriptions herewith given, it 

 will be seen there is a radical difference in the sucking parts, the 

 Therevidae, Nemistrinidae, Mydaidae, Apioceridae, and, I may also 

 add, the Bombyliidae (6), agreeing closely on the one side, and the 

 Asilidae presenting a markedly different and constant type on the 

 other side. 



Again, arguments drawn from the neuration are to me very strong. 

 It is well known that the neuration of the Asilidae, and especially of 

 the Asilinae, is very constant. In a large proportion of the species, 



