704 On Aquatic Carnivorous Coleoptera or Dijtiscidce. 



In the male the front tarsi are small, their claws nearly equal and rather short, 

 the palettes of the undersurface are small and oblong, and the pubescent area 

 moderately large : on the intermediate tarsi the basal joints are quite bare, but the 

 third one bears a broad patch of rather long very dense hairs, the claws are simple 

 and equal. The female has a dense but rudimentary and obsolete sexual sculpture 

 on the wing-case, consisting of excessively fine, short and dense, irregular or curved 

 scratches, these are most distinct at the base, become obsolete before the apex, and 

 also towards the suture and lateral margin. 



The species varies somewhat in size, and in the colour of the uppersurface, which 

 shows sometimes a distinct metallic reflection, while sometimes the scutellum is 

 more or less flavescent ; the yellow colour of the undersurface is sometimes 

 somewhat embrowned in parts, this being perhaps due to decomposition : the spine at 

 the outer angle of the hind femora is sometimes more prolonged and distinct than in 

 other cases. The sulcation of the prosternum is peculiar, and seems to be formed 

 by two very obsolete slightly raised lines proceeding from each front angle of the 

 middle portion, and extending backwards about as far as the lower part of the 

 coxae. 



Australia, Tasmania and New Zealand ; (apparently very abundant and widely distributed Ln 

 Australia). 1116. 



1102. Cybister hookeri. White, Tragus liookeri, M.C — Ovalis, sat convexus, 

 supra niger, capite anterius prothoraceque ad latera testaceis, ely tris vitta marginali, 

 posterius angustissima, testacea ; subtus nigro-piceus, pedibus anterioribus testaceis 

 femoribus in medio piceis, pedibus intermediis piceo-testaceis ; femoribus pos- 

 terioribus angulo posteriori-externo acuto, parum producto ; prosterno anguste 

 obsoleteque sulcato. Long. 25, lat. 13 m.m. 



This species is closely allied to Cybister scutellaris, but is readily distinguished 

 by the colour of the undersurface ; the groove of the prosternum though formed in 

 a similar manner to that of C. scutellaris, differs by the lines which bound it be- 

 coming more approximate, and also by its being continued along the prosternal 

 process. The sexual characters in male and female are almost indentical with those 

 of C. scutellaris. The few specimens I have examined show very little variation. 



New Zealand. 1117. 



I. 7%.— Genus MEGABYTES. 



Coxal lines present ; unguicular cleft narrow and angular at base ; hind tarsi in 

 the male sex terminated by two distinct claws ; (females always with two claws, 

 but the inner one frequently small and rudimentary). 



