100 THE CANADIAN ENTOMOLOGIST. 



more than three times as long as thick at base ; maxillary 

 palpi 6-iointed ,; labial palpi 4-jointed. 



(Australia) Catocheilus, Guerin. 



(Type C. Klugii, Guer.) 



12. Clypeus produced anteriorly, trapezoidal, the front margin squarely 



truncate and overlapping the mandibles, the labrum invisible : 



abdomen not smooth, more or less punctate   13- 



Clypeus very similar but not so much produced anteriorly, the man- 

 dibles wholly exposed, the labrum more or less visible ; abdomen 

 smooth, shining, or at most with fine, microscopic lines. 



Labrum narrowly transverse or arcuate, not bilobed ; hypo- 

 pygium ending in an acute spine, the lateral margins slightly 

 arcuate, the basal angles with usually a slight lobe, but not 

 acute enough to be considered a tooth ; mandibles bidentate, 

 the outer tooth the longer and larger; maxillary palpi 6 jointed, 

 the three last joints much slenderer than the preceding joints, 

 the last joint not longer than the penultimate ; labial palpi 



4-jointed Myrmecodes, Latreille. 



(Type Tiphia pedestris, Fabr.) 

 Labrum bilobed ; hypopygium ending in a spine which curves 

 slightly upwards, the lateral margino almost straight. 



Maxillary palpi 6-jointed, the last joint longer than the pe- 

 nultimate ; labial palpi 4-jointed. 



(Australia) Guerinius, Ashm., gen. nov. 



(Type Thynnus flavilabris, Guer.) 



13. First ventral segment unarmed 14. 



First ventral segment armed with a prominent median tooth. 



Head more than twice as wide as thick antero-posteriorly \ 

 abdomen maculate ; maxillary palpi 



6-jointed Agriomyia, Guerin. 



('I'ype A. maculata, Guerin.) 



14. .Abdomen ovate, maculate, the hypopygium oval, ending in a short 



spine ; maxillary palpi 6-jointed, the three last joints longer than 

 the first three ; labial palpi 4-jointed, the joints 



short Cephalothynnus, Ashm., gen. nov, 



(Type Thynnus odyneroides, Westw.) 

 .A.bdomen fusiform, longer than the head and thorax united, the hypo- 

 pygium triangularly pointed, the sides only slightly arcuate ; 



