28 Cameron, Hymenoptei'a Orientalia. 



longer than the head and thorax united ; the third joint 

 is shghtly, but distinctly, longer than the fourth. Head 

 nearly as wide as the mesothorax, shining, impunctate, 

 the front and vertex thickly covered with fuscous 

 pubescence ; the lower part of the front, the clypeus and 

 the labrum thickly covered with long, white hair. The 

 middle of the vertex and the ocellar region bounded by a 

 deep furrow ; that on the former deeper behind ; the front 

 is deeply depressed above the antennae. Apex of clypeus 

 roundly, but not deeply, incised ; the labrum slightly 

 depressed, its apex rounded ; the apical joints of the 

 palpi are fuscous, paler at the base. Thorax smooth, 

 shining, impunctate, thickly covered with fuscous hair ; 

 the prothorax, mesonotum with scutellum and the greater 

 part of the mesopleurse above, sanguineous ; the furrows 

 on the mesonotum deep, that on the middle lobe wider 

 and shallower ; the middle lobe ends at the apex in a 

 keel. Cenchri large, cream-coloured ; the space between 

 them rufous. All the trochanters, the apices of the coxae, 

 the base of the hinder femora, the four anterior tibiae, the 

 basal two-thirds of the basal pair and the base of the 

 anterior tarsi white ; the claws unequally bifid. The second 

 and third cubital cellules are equal in length above ; below 

 the third is the longer ; both the recurrent nervures are 

 received in the basal third of the cellules. Abdomen 

 blue-black, shining ; the third segment and the base of 

 the fourth dirty white. 



Siobla is intermediate between the Tenthredinides and 

 the Selandriades. The transverse basal nervure is united 

 to the base of the cubital as in the Tenthredinides, but it 

 has more the form of the Selandriades. The antennae are 

 short and thick ; the eyes are large, and reach near to the 

 base of the mandibles ; the spurs are short, not one-fourth 

 of the length of the metatarsus ; the claws are bifid ; the 



