AMERICAN HYMENOPTERA. 9 



Nematns agilis. — ^. — Small, slender; head white, occiput confluent 

 with a large ovate spot on vertex covering the ocelli, and tips of mandibles 

 black; eyes prominent, nearly round ; antennre as long as body, slender, black 

 above, dull luteous beneath, three basal joints of the flagellum of nearly equal 

 length; thorax black above, yellowish beneath, sometimes a black line be- 

 neath wings; posterior angles of prothorax and tegulae white; wings hyaline, 

 iridescent, nervures fuscous, stigma dull luteous, second submarginal cell re- 

 ceiving the first recurrent nervure about one-fourth from the base and the 

 second about one-eighth from the tip, third submarginal less than half the 

 length of second, quadrate; legs slender, yellowish, posterior tibife above and 

 at tip and all the tarsi, more or less fuscous; abdomen narrow, elongate, black 

 above, the lateral margin varied with yellowish; venter entirely yellowish. 

 Length .18 inch. 



Hah. — Nevada, (Morrison). 



Nematus nevadensis. — 9- — Small, robust, honey-yellow; large spot 

 on vertex, extending back to occiput and sometimes to base of antennse, some- 

 times much reduced and disconnected from occiput, tips of mandibles, antennse, 

 mesothorax, sometimes the scutellums and narrow space beneath wings, basal 

 plates, and more or less of the basal middle of the first three or four segments 

 of abdomen above, black; face and mouth parts whitish; antennse shorter than 

 usual, slender, three basal joints of flagellum of nearly equal length; some- 

 times the sides of the middle lobe of mesothorax are honey-yellow; wings 

 hyaline, faintly tinged with yellowish, iridescent, nervures fuscous, most of 

 stigma and nervures at base of wing pale luteous; second submarginal cell 

 receiving the first recurrent nervure about one-fourth from base and the 

 second rather less than one-fourth from tip, third submarginal about half 

 the length of second, longer than broad and wider at tip; tips of posterior 

 tibise and of the tarsi more or less dusky; abdomen short, broad-ovate. 

 Length .17 inch. 



^. — More slender, antennse longer, sometimes the abdomen above except 

 lateral margin and apex, is black; legs entirely honey-yellow. Length .15 — 

 .17 inch. 



Hab. — Nevada, (Morrison). Allied to ayilis. 



Neniatus pectoralis. — ?. — Dull honey-yellow or fulvo-luteous, shin- 

 ing: an ill-defined spot on vertex covering the ocelli, occiput, tips of mandi- 

 bles, antennse, middle lobe of mesothorax except sides, lateral lobes more or 

 less, two large rounded spots sometimes confluent, on pectus, scutellum except 

 base, postscutellum, basal plates, base of all the coxae, four anterior femora at 

 base beneath, and the abdomen above except extreme sides and tip, black; 

 sometimes the middle lobe of mesothorax and the scutellum are entirely dull 

 honey-yellow or fulvo-ltiteous; antennas slender, more than half the length 

 of the body, three basal joints of the flagellum of nearly equal length; tegulae 

 whitish; wings hyaline, nervures fuscous, costal nerve and stigma pale luteous ; 

 second submarginal cell receiving the first recurrent nervure about one-third 

 from the base, and the second near the tip, third submarginal cell more 

 than half the length of second, widened to tip; tarsi more or less dusky. 

 Length .27 inch. 



Hab. — Colorado, Nevada, (Morrison). 



TRANS. AMER. ENT. SOC. VIII. (2) JANUARY, 1880. 



