1930 ] 
Australian Bees 
153 
3 9, Halifax, Queensland (Williams). The type July 
11-20, 1915; two others June 20 — July 9, 1919. From H. 
pavonellus Ckll. it is known by the larger head, with more 
produced clypeus, green mesothorax and clear red hind 
tibiae. 
Halictus williamsi n. sp. 
9 . Length about 5.5 mm., anterior wing about 3.7 ; 
head broad, round seen from in front, very dark green, 
with thin hoary pubescence on face and front; mandibles 
bright red apically; clypeus dull, with very dense lineolate- 
reticulate sculpture; supraclypeal area brassy, also with 
lineolate sculpture, but a little more shining; front dull; 
antennae black, the flagellum obscurely reddish beneath 
apically; mesothorax and scutellum dull, yellowish green; 
metathorax dark green, the rather large basal area coarsely 
plicate, with heavy obtuse margin, which is microscopically 
sculptured all over; tegulae clear fulvous; wings hyaline, 
faintly dusky; stigma dark brown, nervures brown, outer 
recurrent and intercubitus almost obsolete; second cubital 
cell broader than high; femora black, knees, tibiae and 
tarsi bright ferruginous; hind spur as in H. subcarus; ab- 
domen very broad, shining black conspicuously but thinly 
pruinose-pubescent, especially on apical part ; hind margins 
of tergites coppery reddish ; surface of tergites microscopi- 
cally transversely lineolate, and with perhaps a faint me- 
tallic cast ; venter with much white hair. $ , Much smaller 
and more slender, length hardly 3.5 mm., antennae black, 
flagellum not very long; no light mark on clypeus; meso- 
thorax dull olive green, scutellum more shining; abdomen 
narrower. 
Queensland (Williams) . 1 9, Halifax, June 20 — July 9; 
1 $ , Babinda, April 8-16, 1919. 
Female H . williamsi is easily known from H. mundulus 
Ckll. by the dark stigma, and from H. urbanus Sm. by the 
color of mesothorax and appearance of the abdomen. The 
male may be compared with H. hackeriellus Ckll., from 
which it is known at once by the red tibiae, and dull dark 
front of head. 
