SCENOPINIDAE OF THE WORLD 15 



Astoma Lio.y, 1864, p. 762. 

 Scaenopius Dalla Torre, 1878, p. 161. 

 Lepidomphrale Krober, 1913, p. 182. 

 Archiscenopmus Enderlein, 1914, p. 25. 

 Lucidomphrale Krober, 1937, p. 222. 

 Omphralosoma Krober, 1937, p. 222. 

 Paromphrale Krober, 1937, p. 222. 



Type-species, Musca fenestralis Linnaeus (monobasic) . This genus 

 is the largest, and by far the most cosmopolitan, genus, having repre- 

 sentatives in all geographic regions. Because of its size (111 species) 

 it has been subdivided into four infrageneric groups each \vith rather 

 distinct continental distribution: Fenestralis, Albicinctus, Brevicornis, 

 and Velutinus. 



Fenestralis group. — The members of this group are characterized 

 by a head that is higher than long, generally with long slender antennae, 

 R4 branching from R5 at or before the middle of the cell; generally 

 robust and of large size. The males have in common a four-lobed ninth 

 tergum and a three-pronged genital apparatus consisting of a median 

 aedeagus and two lateral aedeagal parameres. The females of this group 

 have a large membranous bursal area; see figures. 



Geographically this group is Palearctic with an extension down the 

 west coast of the North American continent. Scenopinus fenestralis and 

 S. glabnfrons have become world-wide in distribution as a result of 

 transport in trade goods. S. niger, contrary to previous reports, is 

 strictly limited to the European continent. 



Albicinctus group.^ — The members of this group are characterized 

 by having the head higher than long, the antennae only twice as long 

 as wide, the vein R4 branching from R5 near to or beyond the middle 

 of the cell and their size generally smaller than that of members of 

 the Fenestralis group. The males are characterized by a bilobed ninth 

 tergum which does not overlap or close on the ventral side (dorsal 

 on the specimen) leaving the genitaha exposed. The aedeagus is vari- 

 able, with the parameres often longer than the aedeagus proper. The 

 bursa of the female is generally as in the Fenestralis group but 

 somewhat wider than long. 



The members of this group are found in the Ethiopian, circum- 

 Mediterranean area of the Palaearctic, the Oriental and Australian 

 regions including Hawaii. 



Brevicornis group. — The members of this group have the head 

 higher than long, the antennae generally jiear-shaped. The wing has 

 R4 branching from R5 at or near the middle of the cell. Ml tends to 

 run parallel to R5 so that they are widely separated at the wing mar- 

 gin. The male terminalia, though open ventrally, have the proximal 

 portion of the ninth tergum extending ventrally to partially cover the 



