32 PERCY SLADEN TRUST EXPEDITION 



wings more or less dusky, strongly so at apex, stigma and nervures piceous ; first r.n. 

 joining second t.c. ; second s.m. small, narrowed to a point above ; length of first s.m. below 

 about equal to that of the other two combined (about 375 fi); outer side of third s.m. with 

 a single gentle curve ; outer nervures not at all weakened ; legs black, with dull white 

 hair; small joints of tarsi reddish ; abdomen black, with narrow tegumentary yellow bands 

 along apical margins of first three segments, that on third interrupted in middle; sculpture 

 of abdomen feeble ; first segment smooth, with scattered very minute punctures visible 

 only with compound microscope ; second and third with fine transverse striae ; no hair- 

 bands ; stipites very broad, broadly rounded at end. 



Locality. Aldabra 1908 (./. C. F. Fryer). The type is labelled 312, which shows 

 that it was taken on Esprit Island, December 27. 



The unique specimen is in poor condition, with the wings matted, but the species is 

 so distinct that it will be easily recognized. It is doubtless endemic, and its nearest 

 relative, so far as known to me, is H. jlavointtatus W. F. Kirby, from Socotra. H. flavo- 

 vittatus differs in several particulars, for instance, the postscutellum is not yellow. 



3. Halictus [EvylcBus) nicolli, sp. nov. 



$. Length about 8 mm., black, with dull white or greyish-white pubescence; structure 

 quite ordinary; head broad, eyes very black, face with shoi-t dull white hair; mandibles 

 with the apical half dark reddish ; antennae black, the apical part of the flagellum broadly 

 suffused with ferruginous beneath ; clypeus slightly shining ; mesothorax dull, exceedingly 

 minutely punctured ; scutellum more shining ; area of metathorax large, covered with fine 

 anastomosing ridges, the intervals shining ; posterior truncation rather small and in- 

 distinct ; tegulaj shining dusky rufous ; wings clear, iridescent ; nervures and stigma 

 reddish sepia ; outer nervures evanescent ; first r.n. joining second s.m. at extreme apex ; 

 second s.m. little narrowed above ; legs black, with pale hair, small joints of tarsi dark 

 reddish ; anterior tibise ferruginous in front ; a bright red brush at end of hind basitarsus; 

 abdomen dullish, very minutely punctured, hoary with pale hair, especially the apical 

 half; second and third segments with very strong greyish-white basal hair-bands, basal 

 band on fourth not quite so dense, but covering more than half of segment. 



The following characters are microscopical : 



Hind spur with about three spines, the last a mere short lamella ; third antennal 

 joint distinctly longer than fourth ; mesothorax with a minutely tessellate sculpture, and 

 rather numerous small punctures ; scutellum sculptured like mesothorax, postscutellum 

 covered with creamy-white tomentum ; abdomen distinctly though very minutely 

 punctured on first segment. 



^. Length about 7 mm., more slender; clypeus wholly black; flagellum dull ferru- 

 ginous beneath ; knees, tibiae and tarsi ferruginous, but the hind tibiae have a large black 

 patch in front, and the apical joint of tarsi is darkened basally; abdominal bands evanes- 

 cent. The antennae are not very long. 



Localities. Female (type) from Aldabra {li. P. Dupont); British Museum, 1907 — 72. 

 Male from Assumption Island {R. P. Dupoyit, 1909). For an account of both Aldabra 

 and Assumption, see M. J. NicoU, Three Voyages of a Naturalist (1908), chapters xi. and 



