42 
MEMOIRS OR THE QUEEN SLANV MUSEUM. 
Halictus excusus sp. n. 
Male. Length about 7-5 mm. ; slender, black, with a large triangular 
cream-coloured mark on clypeus (but labrum and mandibles black) ; antennae 
very long, flagellum moniliform, entirely black ; tubercles black ; tegulae dark, 
with a red spot ; legs black, the tarsi with dense white hair on inner side ; 
abdomen black, densely and rather coarsely punctured, extreme bases of third 
and fourth tergites red, only visible when much extended. Head rather broad ; 
face covered with white hair ; hair of thorax above dilute brownish ; meso- 
thorax entirely dull, it and the scutellum excessively densely punctured ; area 
of metathorax semilunar, dull, rugulose, with dense vermiform rugae, and no 
shining rim ; wings hyaline, faintly dusky along outer margin ; stigma dull 
reddish, with darker margin ; nervures fuscous ; second cubital cell broad, 
receiving recurrent nervure just before end ; abdomen moderately shining, 
without hair bands or spots ; conspicuous erect pale hair on first tergite ; 
venter with bands of white hair. 
Pyengana, Tasmania, Dec. 31, 1915 (F. M. Littler). Runs in my table 
to H. lanariellus Ckll., but is separated at once by the entirely dull mesothorax. 
Halictus viridarii sp. n. 
Male. Length about 7 mm. ; black, rather stout, with a broad trans- 
verse pale-yellow band on clypeus ; labrum black ; mandibles faintly reddened 
apically ; antennae long, reaching postscutellum, entirely dark ; tubercles black ; 
tegulse rufous ; legs black, with thin white hair ; abdomen black, closely 
punctured, hind margins of tergites faintly brownish. Head broad ; face covered 
with white hair ; hair of scutellum and postscutellum white ; mesothorax dull, 
very densely punctured ; scutellum moderately shining ; area of metathorax 
large, shining apically, covered with fine plicae, delicate and confused in middle, 
distinct and straight at sides ; wings hyaline, stigma dilute brown ; nervures 
pale brown, becoming colourless apically ; second cubital cell large, but higher 
than wide, first recurrent nervure meeting intercubitus ; abdomen rather broad, 
thinly hairy, with distinct patches of greyish hair at lateral bases of second 
and third tergites ; apex with a dark shining rounded plate ; fringes of ventral 
segments extremely short and scanty. 
National Park, Queensland, Dec. 1919 (H . Hacker) ; Queensland Museum. 
Resembles II. excusus, but area of metathorax and abdomen quite different. 
It may also be compared with II. granulithorax Ckll., II. pulvitectus Ckll., and 
H. baudini Ckll., but is quite distinct. 
Halictus subplebeius sp. n. 
Male. Length about 6-8 mm., anterior wing 5-8 ; black, rather robust, 
the abdomen broad for a male ' elypeus with a broad creamy white band, 
having a slight median extension above ; labrum black ; mandibles dark red 
subapically ; antennas long, entirely black ; face broad ; clypeus short, shining, 
