OF WASHINGTON. 167 



Mesosternal furrow wanting, or shallowly impressed, 

 smooth ; abdomen not especially elongate, the 

 sides never parallel ; plate of first segment usually 

 trapezoidal, ovipositor long; last tarsal joint and 



the pulvillus normal Microgaster Latr. 



7. Hind tibial spurs very long, the inner spur fully two-thirds the length 

 of the basal joint of tarsus ; plate of first segment very narrow, 



linear.. (13) Protomicroplitis Ashm., n. g. 



Hind tibial spurs short, the inner spur scarcely one-third the length of 

 the basal joint of tarsus; plate of first segment variable. 



(14) Microplitis Forst. 



(41) Aphidius ribis, n. sp. 



9- Length 2 mm. Luteous; vertex and occiput, thorax above and 

 ovipositor, black ; flagellum, except base of first joint, brown-black ; dorsal 

 abdominal segments 2-4, the apical half of segment 5, and a spot on apex 

 of segment 6, reddish-brown. 



Antennae i5-jointed, reaching to the middle of abdomen, very slightly 

 thickened toward tips ; flagellar joints 1-3 subequal, about four times as long 

 as thick, or possibly slightly longer, the following joints very gradually 

 thickening and shortening to the last, the fourth joint being about three 

 times as long as thick, the penultimate only a little more than twice as 

 long as thick, the last, the longest joint, almost as long as the two pre 

 ceding united. Metathorax smooth, with median and lateral carinae. 

 Wings hyaline, the veins pale, tinged with brownish. Abdomen long, 

 lanceolate, one-third longer than the head and thorax united. 



rf . Agrees with the female, except that the antennae are longer than 

 the body, filiform, iS-jointed, the flagellum black, the joints all delicately 

 fluted, subequal in length, on an average about 23- times as long as thick, 

 except the last, which is nearly twice as long as the preceding, with some 

 times an indistinct suture dividing it into two joints; mesopleura black 

 ish; while the abdomen, except petiole, is mostly brown. 



Hab. Cambridge, Mass. (Bred from Aphis rtbts.) 



FAMILY ICHNEUMONID^E. 

 (47) Hypotherentes geometrae, n. sp. 



C^. Length 4.5 mm. Black; scape, except a lateral stripe outwardly, 

 pedicel, ring-joint, fore femora, except tips, the middle femora and the 

 tibiae, except tips, and hind coxae and femora, ferruginous ; mandibles, 

 palpi, tegulae, anterior and middle legs, except as noted, hind trochanters, 

 knees, a band on middle of hind tibiae, tibial spurs, basal half of first 

 joint of hind tarsi and sutures of following joints, white; hind tibiae, with 

 a black annulus near base, and their apical one-third, black; hind tarsi, 

 except as already noted, fuscous ; flagellum brown-black. 



Head transverse, closely punctate, the face with sparse glittering or 

 silvery pubescence ; eyes large, extending almost to base of mandibles 



