712 BOSTON JOURNAL 



suture before the scutel impressed [261] and with elevated 

 lines: wings liyaline ; nervures fuscous, light brownish towards 

 the base ; stigma triangular, fuscous ; second cubital cellule des- 

 titute of the exterior nervure ; terminal nervures obsolete : ter- 

 gum M'ith large close-set punctures ; towards the tip somewhat 

 polished ; first segment with a yellow lateral margin, dilating a 

 little towards the tip; third segment with a yellow point on the 

 lateral margin : abdomen each side and beneath, except at tip, 

 yellowish : oviduct black, nearly as long as the abdomen, with 

 rather long hairs : feet honey -yellow ; posterior tibire, excepting 

 at base, black : posterior tarsi blackish, with the incisures pale. 



$ Coxae and anterior pairs of tibiae and tarsi whitish : poste- 

 rior tibia), at tip only, dusky, at the extreme base whitish ; se- 

 cond cubital cellule complete; terminal wing nervures distinct. 

 Length % over one-tenth, 9 less than three-twentieths of an 

 inch. 



2. ]\f. MELLIPES. — Black; thorax with oblique, lined sutures; 

 feet honey-yellow. 



Inhabits Indiana. 



% Body black : hypostoma somewhat prominent along the mid- 

 dle : stemmata rather prominent : antennae beneath towards the 

 base piceous : mandibles honey-yellow : palpi blackish or fuscous : 

 thorax with two oblique impressed lines confluent behind, in 

 which are several transverse lines ; and a transverse more dilated 

 one at the base of the suture ; wings hyaline ; nervure of the ra- 

 dial cellule as distinct as the others; second cubital cellule de- 

 stitute of its terminal nervure ; apical nervures less distinct than 

 the discoidal ones, but not obsolete : tergum somewhat fusiform, 

 polished, a little hairy at base and tip : venter at base honey-yel- 

 low, pale : thighs and coxae honey-yellow : tibizB and tarsi dusky. 



Length nearly three-twentieths of an inch. [ 262] 



Distinguished at once from the ensiger by the oblique thoracic 

 lines. 



3. M. XYLINA. — Tergum at tip polished ; sides of the venter 

 yellowish. 



Inhabits Indiana. 



Body black, much punctured: antennae brownish beneath: 

 palpi white : thorax destitute of oblique lines, but with the 



[Vol. I. 



