NORTH AMERICAN HYMENOPTERA. 195 



M ut ilia hexagona Say. 



Male. — Head black, transversely rounded, not as wide as the thorax, closely 

 punctured, thinly clothed with short, erect, silvery hairs ; scape of antennre 

 tufted with silvery pubescence, flagelluni blackish fuscous ; eyes ovate, emargi- 

 nate, ocelli distinct; mandibles black. Thorax black, closely punctured and 

 having four slightly impressed, longitudinal lines on the disc, thinly clothed with 

 erect pale hairs, more dense on the prothorax ; scutellum rounded ; metathorax 

 roundly truncate, with reticulate punctures, dorsal groove not extending to the 

 middle ; wings purplish fuliginous, marginal cell ovate rounded at apex ; first 

 submarginal cell elongate quadrate, narrowed towards base, second submarginal 

 smaller and sharply pointed towards the base, receiving the first recurrent ner- 

 vure at middle, its apical nervure arcuate ; third submarginal hexangular, re- 

 ceiving the second recurrent nervure a little beyond the middle, its apical angles 

 with abbreviated nervures ; a transparent line crosses the first submarginal cell 

 at right' angles to the costa and continues longitudinally through the second and 

 third submarginal cells, and a similar spot in the third discoidal cell ; tegulpe 

 polished. Legs black, clothed with whitished hairs, calcaria white. Abdomen : 

 basal segment black, finely punctured ; second segment dark honey yellow, finely 

 and remotely punctured, its apical margin and remaining segments rufo-fuscous, 

 fringed on the apical margin with pale ferruginous pubescence, ventral surface 

 same as above, with the exception of a dark stain as base of second segment. 

 Length 13-18 mm. ; expanse of wings 18-25 mm. 



Hab. — Indiana, Missouri, Kansas. 



var. a briaxtjs Blake, has the apical margins of the abdominal segments more 

 densely clothed with black pubescence, and having the dorsal groove of the meso- 

 thorax more distinct. 



var. fi vigilans Say, has the marginal cell truncate at tip, the dorsal groove 

 of the metathorax extending beyond the middle. Abdomen : the second seg- 

 ment with large remote punctures, bright rufous, the basal and apical margins 

 black. 



Since the publication of the Synopsis (1871) much more material 

 has been collected from all parts of North America, among which I 

 have been fortunate in obtaining M. hexagona of Say. On close 

 examination briaxus and vigilans prove to be only varieties of 

 hexagona. 



II nl il hi Grotei Blake. 



Male. — Head and thorax black, head not as wide as the thorax, rounded, closely 

 punctured, clothed with short black hairs ; antennre blackish, scape rufous, 

 clothed with glittering pubescence ; eyes ovate, emarginate. Thorax robust, 

 subquadrate, rounded behind, thinly clothed with short black hairs, pro- and 

 mesothorax closely punctured, the latter elevated, metathorax coarsely reticulate, 

 abruptly rounded ; wings ample, pale fuliginous, marginal cell large, sublanceo- 

 late, gradually rounded to tip, three distinct submarginal cells, the first nearly 

 as long as the marginal, second not quite as long as the first, receiving the first 

 recurrent nervure in the middle. Legs black, clothed with fulvous hairs, calcaria 

 whitish. Abdomen elongate ovate, basal segment black, closely punctured, 



