294 A. L. MELANDER. 



6. Mulilla donse-ante Ckll. and Fox (9). 



One female, Mesilla Park, New Mexico (Cockerell). 



7. IWutilla Wickhami Ckll. and Casad. f 10). 

 One female, Fedor, Texas (Birkman). 



Group simillima. 



8. Vlni jlla hi on I i\ aga Cresson (15). 



Plate IV, fig. 2 ; petiole of brazoria. 



Occurring at Austin and Fedor, Texas, in the variations monti- 

 vaga to brazoria. April to October. 



9. >l ill ilia liippodamia Fox (16). 



Plate IV, tig. 42; pygidium. 



One specimen, in a lot of simillima collected by the Rev. G. 

 Birkman at Fedor, Texas, apparently belongs to this species. 

 While otherwise closely resembling the variable simillima, it is aber 

 rant in the widely diverging striae of the pygidium and in the 

 rounded sides of the metathorax. 



Of the type specimens of this species one has the antennae red 

 instead of blackish. The pygidium is transversely rugose, and not 

 longitudinally so, as stated in the key (see fig. 42). 



10. Mutilla simillima Smith (17). 



Plate IV, fig.l; petiole. 



Mass., Penna., Va., Ky., 111., Tex. (M. C. Z., etc.). 



The specimens in the Philadelphia Academy of Natural Sciences 

 determined as this species have no black on the venter nor on the 

 second dorsal segment. No hairs arise from the punctures of the 

 abdomen. Specimens from Texas (Fedor, Birkman) are more or 

 less black caudally and ventrally and have very sparse erect abdomi- 

 nal hairs. The species metis, liippodamia, and simillima can be 

 quickly separated by the sculpture of the pygidium. In metis the 

 striae diverge widely, in typical simillima they are closely placed 

 and more strictly longitudinal, the only divergence being at the 

 very tip of the median ones ; in hippodamia the striae are rugose, 

 straight and transverse. The Massachusetts specimens are consid- 

 erably smaller as a lot and have the lighter spots of the second 

 abdominal segment round. They are variable in the definiteness 

 of the pygidial sculpture, the striae of which sometimes are quite 



