[187] HYMENOPTERA 1 93 



smooth and shining, except the petiole which is almost as long as 

 segments 2 and 3 united, and longitudinally striate or aciculate. 



Type. Cat. No. 5583, U. S. Nat. Museum. From Sitka, June 

 16; St. Paul Island (Fur Seal Commission). 



Genus Thestis Forster. 



THESTIS TRICINCTA sp. nov. 



Female. Length 3.5 mm. ; ovipositor about half the length of the 

 abdomen. Polished black, except the petiole and second segment of 

 the abdomen which are opaque and coriaceous ; the abdominal seg- 

 ments 2 and 3 at apex are yellow, while the extreme apex of the fourth 

 segment has a testaceous tinge ; clypeus, mandibles, palpi, tegulas and 

 the anterior and middle coxae and trochanters are yellowish-white ; 

 rest of legs, except the front pair and the hind pair in part, ferru- 

 ginous, the front legs yellowish, the hind coxae and femora black, 

 their tarsi fuscous ; flagellum brown, yellowish beneath near base. 

 Eyes very large, convergent below and leaving no malar space. 

 Thorax with the parapsidal furrows distinct, converging and uniting a 

 little beyond the middle of the mesonotum. Metathorax constricted at 

 base, completely and strongly areolated. Wings hyaline, the stigma 

 and veins light brown. 



Type. Cat. No. 5598, U. S. Nat. Museum. From Popof Island, 

 July 8; Unga, July 7. 



This is one of the genera placed by Forster in this group ; I think 

 it should be removed to the tribe Plectiscini. It seems to fall in 

 naturally between Symphylus and Eusterinx. 



Genus Aclastus Forster. 



ACLASTUS RUFIPES sp. nov. 



Female. Length 3.2 mm. ; ovipositor shorter than the petiole. 

 Polished black : palpi fuscous ; legs, except hind coxae, ferruginous, 

 the tibial spurs and tarsi paler, the hind coxae black. Antennae 21- 

 jointed, brown-black, the pedicel yellowish, the first joint of the 

 flagellum more than thrice longer than thick, longer than the second. 

 Metathorax short, wrinkled and completely areolated, the areola hexag- 

 onal, wider than long, the petiolar area very long. Abdomen broadly 

 oval, smooth and polished, except the petiole which is longitudinally 

 striate. 



Type. Cat. No. 5999, U. S. Nat. Museum. From St. Paul Island, 

 August 1 6 (Fur Seal Commission). 



