760 BOSTON JOURNAL 



STIGMUS Jur. Latr. 



1. S. PARALLELUS. — This species resembles the fraternus nob. 

 but it may be distinguished by the following comparative char- 

 acters. The posterior thighs and middle of the tibiae are black. 

 The stigma is a little smaller. The dividing nervure of the first 

 and second cubital cellules is parallel to the posterior nervure of 

 the second discoidal cellule ; whereas in the fraternus, the latter 

 is more oblique. 



The size is much the same. 



Inhabits Mexico. 



The Stiymus fraternus, is not uncommon in Indiana, and as in 

 the present species, the hypostoma of the male is somewhat sil- 

 very. 



2." S. PUSiLLUS. — Petiole obsolete : second cubital cellule 

 large. 



Inhabits Indiana. 



Body black, polished : head before, and mouth, including the 

 mandibles, whitish : antennae honey -yellow; basal joint before, 

 whitish : wings hyaline ; nervures pale brownish ; stigma fus- 

 cous; second cubital cellule large, somewhat longer than broad : 

 feet honey yellow ; posterior pair blackish ; abdomen with a very 

 short petiole, almost sessile. 



Length about one-twelfth of an inch. 



This is much the smallest species I have seen. The dividing 

 nervure of the first and second cubital cellules is exactly opposite 

 to the posterior nervure of the middle discoidal cellule. The 

 hypostoma of the female is black, [379] 



PEMPHREDON Latr. 



1. P. MARGINATUS. — Black; antennae at base, mandibles and 

 feet honey-yellow. 



Inhabits Pennsylvania. 



Body polished ; antennae blackish ; first and second joints 

 honey-yellow ; the former as long as the second and third to- 

 gether, which are nearly equal : mandibles honey-yellow, not 

 very obviously denticulated at tip : wings tinted with fuliginous ; 

 nervures brown ; stigma fuscous, not much dilated ; nervures of 



[Vol. I. 



