202 NORTH AMERICAN MUTILLIDAE 



smooth to granular and through various stages of wrinkhng to 

 completely rugose. I can not conclude that its differences are 

 specific; nor are those found in the carina of the petiole. 

 In these four species this carina usuallj^ has an anterior tooth, 

 which sometimes is reduced or wanting or modified in shape. 

 The color is no better. Specimens with an excess of black pu- 

 bescence on the abdomen are in the majority in briaxiis including 

 ornativentris, but individuals of other species approach this con- 

 dition and exceed that of some specimens of briaxus. I am in- 

 clined to think it possible that the amount of black pubescence 

 may to some extent be correlated with locality, as is the case 

 with the blackness of thorax of the male. The amount of silvery 

 pubescence is similarly variable. 



Males 



1. Scape with a dense brush of white pubescence beneath, at apex or along 



entire length. In one species with barred wings this brush is thin, but 

 the hairs are long and white ; ocelli small, the posterior pair distant from 

 the eyes by from two and one-half to five times their transverse diam- 

 eter (2) 



Scape without a brush of white pubescence, nearly nude beneath with 

 moderate, appressed, grey, pubescence above, or with that also largely 

 wanting; wings never barred (6) 



2. Pygidium with a raised longitudinal impunctate, polished platform, strongly 



elevated posteriorly and terminating before the apex of the segment in 

 the flaring arms of a prominent Y-shaped carina, best seen from an apical 

 view, the stem of which reaches the apex of the pygidium in the median 



line; wings fuscous but without a transverse hyaline band (4) 



Pygidium with a low median impunctate poHshed ridge, terminating 

 rather gradually before the apex, there being no carina between its apex 

 and that of the segment; wings with a hyahne transverse band, giving 

 the species a strikingly ornate appearance; basal segment of scape strongly 

 compressed (3) 



3. Scape not carinate, with a very dense brush of long white pubescence; 



clypeus with a median tubercle near its apex; eyes distant from the 

 posterior ocelli by five times the diameter of the latter .... barbata Fox 

 Scape with a strongly raised carina near its apex (sometimes weak), its 

 white pubescence sparse; clypeus without a median tubercle; eyes distant 

 from the posterior ocelli liy three times the diameter of the latter. 



ornatipennis n. sp. 



4. Middle coxae with a strong inner subajiical tooth, pointing Ixickwards; 



.tut)ercles on mesosternum transverse, their anterior margins subtrun- 

 ■cate and nearly vertical; fifth ventral segment and sometimes the sixth 

 without tubercles, the sixth and seventh usually with weak tubercles 

 and the eighth with a moderately strong, ol)liqu(>, dentiform carii.a on 

 •each side (5) 



