FAMILY ASILID.E — THE ASSASSIN FLIES 183 



90. Face with a strong- gibbosity occupying- the lower half or more 



(70, 125) *Erax Scopoli 



Face only weakly gibbous 91 



91. Mystax dense, extending- to above the middle of the face (104, 115, 117). 



Proctacanthella Bromley 

 Mystax sparse, composed of bristles (68) Pachychoeta Bigot 



92. Abdomen without bristles 93 



Abdomen with bristles laterally before the segmental apices 96 



93. Facial gibbosity shining black Rhadiurgus Loew 



Facial gibbosity pollinose, weakly developed 94 



94. Scutellum with at least two bristles 95 



Scutellum without bristles (64, 106) Negasilus, n. g. 



95. Mystax composed of bristles only (116) fAsilus Linnaeus 



Mystax composed mostly of very fine hair Antiphrisson Lcew 



96. Occipital cilia abundant, rather long and curved at almost right angle 



at or near the apical third (59) fNeoitamus Osten Sacken 



Occipital cilia shorter and stouter, not strongly curved 97 



97. Facial gibbosity strongly developed and reaching at least to slightly 



above the middle of the face (Tolmerus Lcew) (69) . . . .fMachimus Loew 

 Facial gibbosity weakly developed, not extending above the lower third 

 of the face 98 



98. Dorsocentrals extending in front of the suture (51) ft'erdistus Lcew 



Dorsocentrals not extending in front of the suture 99 



99. Female ovipositor armed at the apex with four or six stout, short 



bristles; forceps of male genitalia strongly curved and leaving a 



large open space on the apical half (114, 120) fPhilonicus Lcew 



Female ovipositor without bristles; male genitalia compact, never 

 leaving a large open space from dorsal view (113, 119). 



fHeligmoneura Bigot 



Alexiopogon, new genus 



Distinguished from Lasiopofjon Loew by the absence of dorsoeentral 

 bristles. The figures of Lasiopogon will serve also for this genus. Geno- 

 type : — Lasiopogon terricoJa Johnson. 



Mallophorina, new genus 



Claws ro])ust, ol)tuse apieally; marginal cell closed and petiolate, 

 the first posterior cell open or closed; antennjE with long, terminal arista- 

 like style; face evenly gently convex or almost flat, and with almost uni- 

 form hair; front and face wide; body rather thickly pilose. Genotype, 



* Mine, 1919, Ann. Ent. Soc. Amer. xii. pp. \0^-irA. 



t Hine, 1909, (Asilus), Ann. Ent. Soc. Amer.. ii, pp. 136-170. 



