54 Cameron, Hymenoptera Orientalia. 



base; so that the absence of the enclosed space on the 

 median segment, and, more particularly, the presence of 

 the longitudinal furrows on the mesonotum, which are not 

 found, so far as I know, in Halictus^ are the only points 

 of distinction between them so far as regards the females. 

 On the other hand the form of the head in the $ is so very 

 different from what it is in Halictus, or indeed in any 

 allied genus, that it cannot be included in it. 



SUDILA BIDENTATA, Sp. nov. (PI. 4, f 5, 5^.) 



Nigra, nitida, sparse pallide hirta; alts hyalinis. 



Long, fere 10 mm. 



Hab. Ceylon {Rothney). 



$ . Head shining, impunctate, sparsely covered with 

 long, fuscous-black hair; a narrow, but distinct, furrow 

 runs from the ocelli, which are bordered behind by a wider 

 and deeper furrow. Mandibles piceous-red, except at the 

 base and apex. Scape of antennae sparsely covered 

 with long black hairs ; the base of the flagellum with 

 short, stiff hairs ; the rest of it bearing a pale down. 

 Prothorax almost glabrous; its basal edge piceous; the 

 mesonotum and scutella sparsely covered with long, 

 black hairs. Median segment with a gradually rounded 

 slope ; its apex covered with long, white hairs. Mesopleurae 

 and mesosternum shining, impunctate, sparsely covered 

 with long, white hairs. On the mesopleurae, near the top, 

 is a wide, oblique, deep furrow, which reaches near to the 

 apex. Wing? hyaline, the nervures and stigma black ; the 

 first transverse cubital nervure is oblique, straight ; the 

 second slightly, the thirdly distinctly, curved. The hair 

 on the legs thick, longish, white on the femora, much 

 thicker and darker coloured on the tibiae and tarsi ; the 

 spurs and claws reddish. Abdomen very smooth and 

 shining, the base glabrous, the apex thickly covered with 

 long, stiff, fuscous-black hairs; the apical ventral segments 

 thickly covered with long, fuscous hairs. 



