336 PERCY SLADEN TRUST EXPEDITION 



42. Hippelates femorata, n. sp. 



A single specimen labelled " Astove 1907 (H. P. Thomasset) " differs considerably 

 from the above; it has distinctly incrassated hind femora. The specimen is gummed on a 

 cai-d and hence cannot be fully described ; it is so distinct that no difficulty should arise 

 in identification. 



?. Head. Frons yellow with black shining triangle ; hind head completely black 

 but interrupted on the line of the vertex by two yellow spots one each side of the ocelli. 

 Bristles as in H. longiseta, but the crossed post-vertical pair are exceptionally strong. 



Eyes bare. 



Antennae brownish but no detail can be given as they are buried in the gum. 



Thorax. Dorsum black with the central part yellowish the yellow part extending 

 from about the cross suture to the scutellum. The humeri are swollen and yellow 

 with a small brown dot in the centre of each. Pleura yellow. Scutellum black, flattened, 

 punctate, with two long convergent black terminal bristles. 



Wing very like Fig. 21. 



Halters yellow. 



Legs : front and middle yellow but the details are hidden by the gum ; hind legs, 

 femora with proximal third yellow, distal two-thirds black, incrassated ; tibiae, black 

 flattened broadening from each end, on the inner face about the middle is a pale grey spot 

 apparently covered with dust ; the tibial spine is black and stout about as long as the 

 metatarsus ; the tarsi brownish black the joints being rather stout, especially the meta- 

 tarsus which is fringed inside with a close row of pale hairs. 



Abdomen, black, yellowish at the base with narrow yellow margins to the segments. 



Size. 2f mm. 



Locality. Astove Island : 1907 (Thomasset). 



Gaurax, Loew. 



Gaurax Jjoe-w, Berlin. Ent. Zeitschr., vii. (1863), p. 35. 



A pair of specimens seem to be best placed in this genus. Loew in his definition of 

 the genus says " seta subterminali j^lumata." The present insect agrees substantially 

 with his generic description except that the arista is distinctly dorsal. Zetterstedt's 

 Oscinis ejyhijjpium is now considered to belong to this genus, though the arista can 

 scarcely be considered subterminal. Pending a revision of the species it appears best to 

 place the present insect in the genus. 



43. Gaurax seychellensis, n. sp. 



$, ?. Head (PI. 16, fig. 10). Vertex and frons brownish yellow, but pale yellow 

 from the tip of the frontal triangle to the antennae ; frontal triangle dull black with its 

 base not extending to the eye-margins and with the front angle rounded and extending 

 nearly half way to the base of the antennae, the triangle is bordered each side by a row of 

 pale hairs. 



