AMERICAN MUTILLID^. 221 



iu wliich the mandibles are bidentate, and the other groups of the 

 tridentate series seem closer to groups imperialis, hexagona, etc., 

 than to asopus. A natural arrangement of the groups therefore is 

 ap])arently not possible. 



The American generic names which fall into the synonymy under 

 Mniilla are as follows : 



Ephiita Say ^ group occidentalis. 



MiUilla (Liune) Blake = groups hexagona, scrupea. 



Agama Blake (subsequently changed to Photopsis Blake) = groups imperinlis and 



anthophorie. 

 Sphxrophthnlma Blake ^groups occidentalis. pennsylvanica. asopiis, wuco. canadensis, 



simillima, grandiceps. 

 Photopsis Blake ^ groups imperiHlis and anthophorm. 

 Pseiidomethoca Ashmead ^groups simillima, canademsis. 



Epliuta, Say seems to have been overlooked by Blake when he 

 named SpJuerophthalma, as it has priority. The groups represented 

 by Pseudomethoca Ashmead are the American representatives of 

 Myrmilla (Wesm.) Andre. 



The groups into which the North American species of Mutilla are 

 divisible are as follows : 



Mandibles tridentate iu both sexes. 



First and secoud abdominal segments sessile. 



Wings of '^ rudimentary; 9 thorax not erenulated. .. -Gr. graiidifeps. 

 Wings of % normal ; 9 thorax crenulated laterally. 

 No pygidium in 9i wings with two submargiual cells. 



Gr. canadensis. 

 A pygidium iu 9; wings with a tolerably distinct third submargiual cell. 



Gr. simillima. 

 First abdominal segment smaller than second, not sessile. 



Wings rudimentary Gr. waco. 



Wings normal Gr. asopus. 



Mandibles bideutate, or in some females edentate; if tridentate they are very 

 robust and almost abnormal (groups imperialis, anthophoras, etc.), and 

 the teeth are situated at apex. 

 Eyes not emarginate anteriorly, rounded or reniform. 



Eyes round, polished, not facetted; marginal cell truncate; mandibles not 



thickened in 'J, Gr. occidentalis. 



Eyes irregularly rounded, or reniform,' generally facetted: mandibles robust 

 in I. 



Ocelli small, round, no pygidium in 9 ■ Gr. pennsylvanica. 



Ocelli large, the anterior one reniform ; 9 with distinct pygidium. 



First abdominal segment ( 9 ) snialler than secoud, more or less nodose ; 

 in % the first and second segments similarly sculptured. ^"siT" 



Gr. imperialis. 



First and secoud abdominal segments (9) sessile; first segment of % 



more coarsely sculptured than second Gr. antltophorte. 



TRANS. AM. ENT. SOC. XXV. JANUARY. l§9»r\^ 



