60 Journal New York Entomological Society. [Voi. xviii. 



examined thirty males of arcnatus, and four of these show this con- 

 dition. Of pcrplcxus I have seen but fourteen males and all but four 

 of these show more or less separation of the facets. Sometimes the 

 line of separation extends nearly around the area (Fig. 3) as it does 

 in pyrastri, but more commonly it fades out on the lower border of 

 the area and is confined to the posterior and a part of the lower 

 sides (Fig. 4). Evidently this character, since here it is not even 

 of specific importance, cannot be urged as a generic character. 



2. SzvoUcn Frons. — This again is most marked in pyrastri, where 

 especially in the male, it reaches its highest development (Figs, i 

 and 6). In albomacttlatus it is less marked, while in scleniticiis 

 (Figs. 2 and 7) it is not more evident than in certain species be- 

 longing undoubtedly to Syrphiis (cf. Fig. 2 with 3 and 4). Verrall:}: 

 has given it as his opinion that " the inflated frons alone is sufficient 

 to differentiate the genus," but after the examination of three species 

 of " Catahomha " and some sixty species of Syrphns I am unable to 

 concur in the opinion. The inflation of the frons is so much greater 

 in the male that it may be looked upon as a secondary sexual char- 

 acter (cf. Fig. I of pyrastri, male, with Fig. 5, female). To my 

 mind there is no more reason for constructing a separate genus on 

 this one character than there would be in the erection of a new 

 genus to include those species, which, like 5". geniculatus Macquart, 

 have a greater protrusion than usual of the lower part of the face. 



3. Reduced Hypopyginm. — Here again we are dealing with a 

 character that has no special generic significance. It is true that 

 in the " Catahomhas " the hypopygium is small and almost or entirely 

 concealed from above under the fifth abdominal segment, but it is 

 also true that in scleniticiis it is much larger than in pyrastri, while 

 in a number of species of SyrpJiiis (grossiilariar Meigen, auricoUis 

 Meigen, protritus O. Sacken, crepcr Snow) it is likewise much re- 

 duced and partially or entirely concealed below the fifth segment. 



4. Pilose Eyes. — Rondani founded his genus Lasiophthicits with 

 pyrastri as the type, on those species of Syr pints which have hairy 

 eyes. The separation on this character is entirely unwarranted in 

 the light of more recent study, as A^errall (I. c.) has pointed out. 

 Verrall further maintains that we may have bare-eyed Catahomhas, 

 " as I possess four specimens of a bare-eyed species which existed 



t Br. Flies, Syrphidse, 334. 



