On Aquatic Carniworous Coleoptera or Dytiscide. 633 
I. 65.—Genus HY DERODES. 
Yellow colour of clypeus not sharply limited from the dark colour of the front of 
the head ; and this dark colour in the middle extends distinctly on to the clypeus. 
Clypeal suture obliterated in the middle. Elytra unicolorous, destitute of yellow 
border. 
This genus comprises only three species, peculiar to Australia and Tasmania. 
980. ITyderodes shuckardi, Hope, M.C.—Ovalis, robustus, convexus, nigricans, 
superne (preesertim in thorace), nitidus, subviridescens, clypeo et prothoracis 
lateribus testaceis, antennis rufis, pedibus piceis ; prothorace lateribus crasse margi- 
natis, intra marginesm parum impresso ; elytris punctis seriatis conspicuis, punctis- 
que sparsis minutis versus latera et apicem minus subtilibus. Long. 19, lat. 11 m.m. 
Var. feminz, thorace elytrisque opacis, rugosis, quasi profunde erosis. 
The male has the three basal joints of the front tarsi very broadly dilated, and 
coadapted to form a circular plate, which is furnished beneath with large and 
distinctly stalked palettes rather variable in size, the marginal ones being smaller, 
but the four near the base larger than the rest ; the fourth joint is quite simple 
and rather short, the fifth rather long, about equal to the length of the three 
dilated basal joints, the claws are moderately long and a little unequal, the anterior 
one being more curved than the other. The intermediate tarsi have the three basal 
joints much dilated, so as to form an oblong oval plate, which is furnished beneath 
with palettes similar to those of the front feet, but differing less inter se as to size, 
and leaving-a bare glabrous space at the base of the tarsus; on the hind feet four 
joints of the tarsus are furnished beneath rather scantily with fine hairs. The 
female is a little smaller than the male and shows a slight difference in the form of 
the thorax : the second form of this sex with deeply corroded upper surface is very 
remarkable. 
According to the specimens before me the species varies a good deal in breadth, 
and somewhat in colour, the greenish-black tinge of the uppersur face giving place 
sometimes to a piceous tint ; the length and breadth of the prosternal process also 
exhibit a good deal of variation. 
Tasmania, South Australia, New South Wales. 932. 
981. Hyderodes crassus, n. sp.—Ovalis, latus, robustus, convexus, nigricans, 
nitidus, superne subviridescens, clypeo et prothoracis lateribus testaceis, antennis 
rufis, pedibus piceis ; prothorace lateribus haud crasse marginatis, sed intra mavr- 
ginem conspicue depresso; elytris punctis seriatis conspicuis, punctisque sparsis 
versus jatera et apicem minus subtilibus. Long. 19, lat. 112 m.m. 
