SMITH ON HYMEHfOPTEEA OF ARU ISLANDS. 177 



stigma, crossing the submarginal cell; the anterior margin of the 

 anterior wings pubescent ; the metathorax broad, margined laterally, 

 with a central forked carina, and a crooked one on each side ; the 

 posterior legs incrassate. Abdomen with the sides of the upper sur- 

 face carinated. 

 Hah. Aru. 



Fam. CHEYSIDID^, Leach. 



Gren. Stilbum, Spin. 



\. Stilbum splendidum, Fahr. Syst. Piez. p. 1/0. 1. 

 Hab. Aru; Senegal; Java; Bengal. 



2. Stilbum amethystinum, Fabr. Syst. Piez. p. 176. 32. 

 Hab. Aru ; Australia. 



Fabricius includes this insect in the genus Chrysis ; the typical spe- 

 cimen, however, proves that it belongs to the more modern genus 

 Stilbum : it is very distinct from -S. splendidum, being much more 

 strongly and coarsely punctured ; and the teeth which arm the apical 

 segment are diiFerently disposed on the margin. 



Fam. TENTHEEDINIDiE, Leach. 

 Gren. Oetssus, Fabr. 



1. Oryssus maculipennis. O. niger, punctatus ; pedibus ferru- 

 gineis ; alis fuscis fascia hyalina ante cellulam marginalera sita. 



Female. Length 5| lines. Black ; the head rugose, the front coarsely 

 so, with a row of transverse tubercles running from the vertex along 

 the inner orbits of the eyes, and crossing the front at half their 

 length ; the cheeks with a cinereous down, and a line of silvery-white 

 pubescence or down, along the outer orbits of the eyes. Thorax 

 coarsely punctured ; the mesothorax with a central longitudinal 

 smooth elevation ; wings fuscous, with a broad transverse hyaline 

 fascia before the base of the marginal cell, the tips of the wings hya- 

 line ; the legs ferruginous, with the coxae and trochanters black ; the 

 posterior tibiae with a double row of serrations outside. Abdomen 

 shining and closely punctured ; the base and a[)ex coarsely so. 



Hab. Aru. 



Gren. Xyphidkia, Latr. 



1. Xyphidkia rufipes. X. nigra; mandibulis, antennarum scapo, 

 pedibusque ferrugineis ; alis hyalinis et iridesccntibus. 



Female. Length 4 lines. Black and shining ; the vertex highly pohshed; 

 the front from the posterior ocelli forwards closely punctured and opake; 

 the mandibles, scape, and basal joint of the flagellum ferruginous. 

 The thorax anteriorly punctured and opake, posteriorly shining, and 

 with a few punctures at the base of the scutellum ; wings hyaline and 

 iridescent, the nervures black, the extreme base of the wings and the 



12* 



