Kahl: The Dipterous Genus Leucophenga Mik. 367 



Strobl, those who have access to the European species can determine,^"" 

 The chaetotaxy of tlie genera of the DrosophilincE. is much alike 

 with modification in size of certain groups of bristles. Thus Leuco- 

 phenga, Phortica, and Stegana have three strong fronto-orbitals; weak, 

 hair-like postverticals, except in L. ambigua sp. iiov.; and the posterior 

 pair of acrostichals well developed. Drosophila has two strong fronto- 

 orbitals^ and a third small to very minute one between them, postver- 

 ticals strongly developed, while the posterior acrostichals can usually 

 not be differentiated from the minute setulae of the mesonotum. in 

 a small species of a true Drosophila from Bolivia before me the hind- 

 most pair of acrostichals (prescutellar pair) is quite differentiated, 

 but yet the postverticals are strong, even for so small a species. 

 Drosophila graminum Fallen, adusta Loew, and several allied species 

 have properly been placed in a separate genus, Scaptomyza Hardy, 

 both on account of the habits of their larvae as leafminers, and of their 

 long, narrow wings, their wing-venation, acrostichals in few, regular 

 rows, occiput convex (not concave) and the two dorso-centrals far 

 apart. Czerny has erected the genus Chymomyza for D. costata 

 and D. fiiscimana; and the American species D. amccna Loew and 

 procnemis Williston should be referrred to this genus. Both species 

 are more active in their motions than true Drosophila, and I have often 

 observed them during their walk on windows moving their wings in 

 the manner of Sepsids and Ortalids. Their wings are quite long and 

 narrow; legs rather long; mesonotum not so convex as in Drosophila; 

 postverticals extremely minute, hairlike; no prescutellars; three strong 

 fronto-orbitals, two of which are reclinate, one proclinate (the pro- 

 clinate pair strongly converging) , the upper reclinate about the middle 

 of front and the lowermost reclinate situated closer to the eye and 

 quite near the anterior border of the front; the proclinate bristle is 

 situated some distance above and inward of this lower reclinate bristle, 

 which on account of its nearness to the eye corresponds with the middle 

 fronto-orbital (the lower reclinate) in the other genera; front with its 

 sides strongly diverging upwards, and face comparatively narrow. 



lOa After this article was ready to go to press I discovered that I had overlooked 

 the fact that Becker has added a third species of Leucophenga to the European 

 fauna, L. leiicosloma, from Hungary, which he describes in the Annales Hisiorico- 

 Nalurales Musei Nalionalis Hungarici, \o\. VI, 1908, p. 320. As I do not at present 

 have access to his description, I am unable to state whether he has dealt with the 

 chaetotaxy of this and the other European species and has confirmed or refuted the 

 statements of Professor Strobl concerning the fronto-orbital bristles. 



