long's second expedition. 229 



Arpactus Jurine, and of course possesses those oblique parallel 

 lines of the metathorax which Jurine mentions as distinguishing 

 this genus. 



PEMPHREDON Latr. Fabr. 



1. P. CONCOLOR. — Black, minutely punctured; metathorax 

 with dilated punctures ; abdomen glabrous. 



Inhabits North-west Territory. 



Head with minute pubescence, more distinct on the front ; 

 mandibles obtusely bifid at tip, immediately above which are two 

 obtuse teeth ; punctures minute, sparse on the vertex ; thorax 

 with a slightly impressed, longitudinal line, from which proceed 

 numerous, minute wrinkles, curving outwards and backwards, 

 punctures larger than those of the head ; wings slightly fuligin- 

 ous, nervures blackish; metathorax with dilated punctures, or 

 slightly impressed cavities; feet somewhat sericeous; abdomen 

 polished, impunctured ; petiole moderate. 



Length of the body nearly seven-twentieths of an inch. 



This is allied to P. unicolor Fabr. 



2. P. INORNATUS. — Black, immaculate, punctured ; abdomen 

 impunctured, polished ; petiole nearly one-third the length of the 

 abdomen. 



Inhabits Pennsylvania. 



Wings hyaline, very slightly tinged with dusky, the [340] first 

 submarginal cellule receives the two recurrent nervures ; nervures 

 dark fuscous : stigma rather large. 



Length less than three-tenths of an inch. 



STIGMUS Jur. Latr. 



S. FRATERNUS. — Black, antennae and feet yellowish. 



Inhabits Pennsylvania. 



Body deep black, polished, not obviously punctured; mandi- 

 bles and palpi whitish ; wings hyaline, nervures pale brown, 

 stigma piceous-black, whitish at base ; origin of the wings yel- 

 Idwish ; pleura with a white spot rather before the origin of the 

 wings ; feet immaculate ; venter whitish at tip. 



Length rather more than three-twentieths of an inch. 



This species is in the collection of Mr. William W. Wood. 

 It is closely allied to the ater of authors, the petiole of the ab- 

 domen, however, is proportionally longer. 



