172 CHARLES ROBERTSON. 



CERATIAS gn. nov. (Type Megaehile pugnatus Say). 



Females. 



Cheek broad, with a great tooth beneath ; clypeus short, witli a median process 

 and a tubercle on each side; mandibles 5-dentate, inner tooth small. 



pug-natus. 



Cheek unarmed ; clypeus bisinuate, with a median angle and two teeth on each 

 side; dorsal segment 6 with an abrupt apical lip; mandibles 4-dentate, 

 the inner tooth most prominent - sayi. 



Males. 



Middle metatarsus broader than the tibia; front and middle femora and tibiae 

 red; boat-shaped scale subtruncate and with the scale on joint 2 pro- 

 duced to the tip of joint 3 ; front trochanter and coxa yellowish ; front 

 coxa with a single long bristle pollicaris. 



Middle metatarsus narrower than tibia, more or less colored ; front and middle 

 femora and tibiae black, or nearly so; front trochanter and coxa black ; 

 boat-shaped scale somewhat pointed 1. 



1. Scale strongly produced, about equaling the tip of joint 3, at base within with 

 a short line of black pubescence ; coxal bristles 2-3, long, .pugnatus. 

 Scale hardly produced, ahout equaling tip of joint 2, edged with fuscous pu- 

 bescence ; coxal bristles 4-5, short sayi. 



J Gnathodon gn. no v. (Type Megaehile georgica Cresson) georgicun. 



Xanthosarus gn. nov. (Type Megaehile latimanus Say) latimanus. 

 . Cyphopyga gn. nov. (Type Megaehile montivaga Cresson) montivaga. 



Anthemois gn. nov. (Type Megaehile infragilis Cresson) infragilis. 



•I I <. V< lill I Latreille. 

 Females. 



Scopa yellow ; disc of segment 6 in profile straight, with minute appressed black 

 hairs; hind metatarsus narrower than tibia; joint 1 of labial palpi 

 one-fifth shorter than 2 .mendica. 



Scopa white 1. 



1. Posterior ocellus nearer the edge of the vertex than to the nearest eye, the 



edge passing in front of supraorbital line ; segment 6 in profile straight, 

 clothed with appressed sericeous pubescence and long sparse black 

 hairs; hind metatarsus as broad as tibia ; joint 1 of labial palpi one- 

 sixth longer than 2 petulans. 



Posterior ocellus not nearer the edge of the vertex than to the nearest eye. .2. 



2. Disc of segment 6 in profile straight or slightly concave, with minute appressed 



pubescense 5. 



Disc of segment 6 with long erect hairs, more dense and appressed apically. .3. 



3. Hair of segment 6 almost entirely black ; margin of clypeus denticulate ; joint 



1 of labial palpi a little longer than 2 addenda. 



Hair of segment 6 black at base, whitish apically; in profile more distinctly 

 concave before an apical lip; clypeus entire; joints 1-2 of labial palpi 

 equal 4. 



