184 NORTH AMERICAN DIPTERA 



— Mallophora guildiana Williston. Species included : laphroides 

 Wiedemann, clausicella Macquart, acra Curran, all previously placed in 

 Mallophora. 



Negasllus, new genus 



Related to Asilus Linnaeus but at once distinguished by the absence 

 of scutellar bristles. Artista short and style-like; face moderately con- 

 vex on the lower half, the mystax composed of bristles only; occipital 

 bristles straight; four pairs of dorsocentrals on the posterior half of the 

 mesonotum; mesonotal hair all short and appressed; abdomen elongate 

 and without bristles on the second and following segments. Genotype : — 

 N. belli, n. sp. 



N. belli is black, cinerous-yellowish pollinose, the male genitalia, 

 apices of the femora and the tibia reddish. 



