OF NATURAL HISTORY. 739 



Body black, much punctured, and with a slight reflection of 

 silvery hairs, particularly on the head, on the anterior segment 

 of the thorax and on the metathorax: thorax with four slight, 

 impressed lines, and numerous confluent punctures : metathorax 

 reticulate with punctures, and with a slight groove from the base 

 nearly to the middle : wings dark purplish-fuliginous ; radial cel- 

 lule rounded at tip, not truncate ; third cubital cellule [296] 

 rounded hexangular, with abbreviated nervures from the two 

 outer angles ; a white line passes through the cubital cellules, 

 and a white spot is in the outer discoidal cellule : abdomen rufoua 

 or bright honey-yellow ; first or petiole segment black : feet sil- 

 very hairy. 



Length from half an inch to nearly seven-tenths. 



The neuration of the wings is much like that of the 31. itnlica 

 F., even to the white line and small spot ; but the third cubital 

 cellule is still more regularly hexagonal and the radial cellule is 

 not truncate at tip like those of the italica and melanura Klug, 

 and many other species. 



3. M. VIGILANS.— ^ Black; large abdominal segment, ex- 

 cepting its anterior and posterior margins, rufous. 



Inhabits Pennsylvania. 



Body black ; with large, dense punctures : thorax with three, 

 somewhat elevated lines and a slight appearance of another each 

 side : wing-scale convex, lineate on the margin ; the outer and 

 hinder margins lineated with minute, elevated, parallel lines : 

 wings purplish-black ; radial cellule truncate at tip ; first cubital 

 cellule bisected by a white line; second cubital gradually and reg- 

 ularly narrowed to the base, with an abbreviated white line at 

 tip ; third cubital hexagonal, not contracted, the two exterior 

 angles with abbreviated nervures ; exterior discoidal cellule with 

 a white dot : metathorax discoidally punctured ; dorsal groove 

 extending beyond the middle ; large basal segment of the abdomen 

 with large remote punctures, smaller and closer on the sides, 

 bright rufous, its basal and terminal margins black. 



Length over three-fifths of an inch. 



Resembles M. italka F., but difi-ers in greater depth of color 

 in the lineations of the wing-scale, greater length [297] ot the 



1835.] 



