36 THE CANADIAN ENTOMOLOGIST 



femora incrassate, arched above, flattened and concave beneath ; 

 hind tibiae incrassate, whitish above near apex, and below produced 

 into a large flattened white apical lobe, which carries on its surface 

 the widely separated spurs; abdomen claviform, narrowed basally; 

 th /first segment (except a dusky apical cloud), and the second 

 except a transverse band (narrower in middle) clear ferruginous; 

 rest of the abdomen black, with the hind margins of the segments 

 broadly colourless hyaline; venter light red beneath as far as the 

 fourth segment, which is broadly emarginate; fifth segment dull 

 black emarginate. 



9 . — More robust, the produced clypeus very broad, clear 

 ferruginous (as also part of supraclypeal area), flattened and impunc- 

 tate in middle, strongly lobed at sides, the shining sparsely punctur- 

 ed sides of face forming an acute angle on each side between the 

 clypeus and its lobe; labrum and greater part of the broad bidentate 

 mandibles clear red ; sides of face and lower part of front with 

 short golden tomentum; scape reddened apically; apical half or 

 more of flagellum obscurely reddish beneath; hair of thorax 

 (dense on prothorax above) pale fulvous; disc of mesothorax 

 more strongly and closely punctured; area of mesothorax with 

 small basal plicae; first r. n. entering basal corner of third s. m.; 

 third s. m. broader above; legs with golden hair; anterior tibiae 

 and tarsi, and middle tibiae in front, clear red; only the first 

 abdominal segment red, with a pair of subapical brown spots; 

 second segment with the broad apical margin orange; the shining 

 short hairs of the apical margin are golden on the second seg- 

 ment, but white on the others. 



Hab. — Khasia Hills; the male is the type. The female is 

 dated June. The sexes differ sufficiently to suggest that they may 

 represent two species, but they are probably identical. The male 

 is quite similar to the African T. orchidarum Ckll., differing princip- 

 ally by the claviform abdomen with red base, and the much less 

 broadened hind tibia^. The fifth ventral segment of T. orchidarum 

 carries a broad dense brush of hair, wanting in T. sladeni. 



It is perhaps possible that the Indian Halictus wroughtoni 

 Cameron is a ThrincJiostoma, although Bingham's figure of the male 

 shows ordinary hind legs and gives no indication of hair-patches, 

 on the wings. It is in any event distinct from T. sladeni. 



