702 On Aquatic Carnivorous Coleoptera or Dytiscide. 
anterioribus rufis: prothorace margine laterali elevato ; prosterno a margine 
anteriore ad apicem profunde sulcato. Long. 16, lat. 8i m.m. 
In the male the front tarsi are not large ; their claws are peculiar, very unequal 
in length, each has a swelling at the extreme base, and is abruptly bent just 
beyond this, the front one is elongate and slender, while the hind one is much 
shorter and is sinuate ; the undersurface is occupied with rather large, nearly cir- 
cular, palettes, the basal fringing hairs are elongate and well developed, and there 
is no pubescent area between them and the palettes. The intermediate tarsi are 
slender, and without sexual pubescence, but their claws are very unequal in length, 
the outer one being elongate. The female has no sexual sculpture. 
This interesting little species can be readily distinguished from all its allies by 
the fact that the thorax is flattened or depressed close to the side so as to give the 
lateral margin the appearance of being elevated. It varies somewhat in the colour 
of the upper surface, which is in some cases more tinctured with green and with a 
metallic lustre than it is in others. 
Australia, (Swan River). 1118. 
1098. Spencerhydrus latecinctus, n. sp.—Parvas, oblongo-ovalis, sat convexus, 
supra piceo-niger, capite anterius prothoraceque ad latera testaceis, elytris latissime 
testaceo-cinctis ; subtus piceo-rufus, pedibus quatuor anterioribus rufis ; prosterno 
a margine anteriore ad apicem suleato. Long. 182, lat. 10 m.m. 
In the male the front tarsi are moderately large, their claws are greatly and 
abruptly curved, and the anterior one is nearly twice as long as the other ; the 
undersurface is furnished with rather large elliptico-circular palettes, and the basal 
fringing hairs are well developed, there being no pubescent area between these 
and the palettes. The intermediate tarsi are simple, their claws rather elongate 
and slightly unequal. ‘he female is unknown to me. 
This and the following species are readily distinguished from the allies by the 
very broad lateral yellow band of the wing-cases, even at the apex it is very 
broad. 
Australia. 1119. 
1099. Spencerhydrus semiflavus, n. sp.—Parvus, oblongo-ovalis, sat convexus, 
supra viridi-olivaceus, omnium latissime testaceo-cinctus ; subtus testaceus ; pro- 
sterno a margine anteriore ad apicem sulcato. Long. 19, lat. 10 m.m. 
I have seen only the female of this species; it has on the thorax near the sides 
numerous short, rather fine scratches, 
Although probably closely allied to 8. latecinctus, I think this will prove a dis- 
