1911] Study of Muscoid Flies 147 



tions. Pyrrhosia may belong here, and the present form may be 

 that genus or one of its near allies, being apparently what Coquil- 

 lett determines as Leskia. I have no alternative, however, but 

 to name it to prevent doubt hereafter. 



Psetjdodexiine series — There are almost certainly many dis- 

 tinct groups here. The ORPHIRODEXIINE series must be erected 

 for Ophirodexia and its allies. 



Atrophopodine series — This is quite distinct from Ophiro- 

 dexia, as shown by Diaphoropeza peruana sp. nov. (Peru) dis- 

 sected and drawn, TD 402(i. This species is not typical of the 

 genus but comes nearer to it than to any other, and certainly 

 belongs to the Atrophopoda group. Ovaries not large, oviducts 

 very short, common oviduct very long, spermathecal ducts 

 and tubular glands short, preuterus present; uterus thick and 

 swollen, in one coil or so, eggs and maggots very oblique to 

 longitudinal. It is as yet doubtful if Vanderwulpia can be here 

 included. The group is proposed for Atrophopoda and its 

 allies. 



BESKIINE series. — Beskia and allies. No proper material 

 for dissection has yet been available but the group must be 

 pointed out as probably furnishing a most marked deviation in 

 larval habit from any hitherto known in the muscoid flies. 

 In 1908, Mr. E. O. G. Kelley found, at Pawnee, Oklahoma, a 

 maggot which he observed at the time to be, to quote from Mr. 

 Webster's letter on the subject, "in the act of actually feeding 

 on a grain aphid of wheat, probably Macrosiphum granaria." 

 This maggot changed to a puparium which was attached to the 

 base of a wheat leaf. From this puparium issued a fly of Ocyp- 

 terosipho aelops, which is very close to Beskia if not the same. 

 No confirmation of this larval habit has come to light since, but 

 although the record is a most surprising one it is probable that 

 the maggots of these flies are external feeders on aphids and per- 

 haps some other soft-bodied insects. The anal stigmata of the 

 puparium are borne at the ends of long processes which suggests 

 an analogy with aphidophagous syrphids. 



Steinielline series — From what Nielsen has shown of the 

 characters of the first-stage maggot of Steiniella, the genus repre- 

 sents a separate group. This maggot possesses minute colored 

 subchitinized plates interspersed with short spines, some of the 

 plates bearing spines on their posterior edge. The maggots are 

 almost certainly not deposited on leaves. The form is not 



