On Aquatic Carnivorous Coleoptera or Dytiscide. 707 
on the wing-cases, consisting of more or less coarse punctures which are scarcely 
elongated, they vary in the extent of their distribution, sometimes extending along 
half the length of the elytra, but are always widely separated from the outer margin, - 
and only approach the suture at the base; the rudimentary claw of the posterior 
tarsi is not much developed and is only to be seen on the underside of the other claw. 
The species is a variable one in size and colour, and in form is most inconstant, 
being sometimes greatly narrowed in front, sometimes not at all; it possesses a 
scattered fine punctuation on the wing-cases, which also is variable; the sides of 
the thorax are often vaguely ferruginous, but never distinctly yellow. 
_ It may always be distinguished from the following species by the male front tarsi 
and hind claws, by the shorter and less slender antennz and by the deflexed lacinize 
of the hind coxe being nearer to the epipleurz, the female moreover has its sexual 
sculpture tending to spread less towards the outer margin of the wing-cases. 
South America, (Buenos Ayres, Monte Video, Uruguay, Entre Rios, Parana), 1102. 
Grovp 8. 
1106. Dytiscus levigatus, Ol., Trogus levigatus, M.C.—Ovalis, sat latus et con- 
vexus, supra olivaceo-niger, capite anterius prothoraceque ad latera anguste testa- 
ceis, elytris versus apicem plus minusve vage ferrugineo-tinctis vel submaculatis ; 
subtus nigricans, pedibus quatuor anterioribus rufis, posterioribus piceis; antennis 
gracilibus. Long. 214, lat. 125 m.m. 
The male has the anterior tarsi small, attaining 2 m.m. in the transverse direction, 
their claws are only moderately elongate, and are therefore not conspicuously 
unequal in length ; on the undersurface the palettes are rather narrow, the basal 
fringing hairs are rather fine and moderately short, and at the heel diverge much 
from the palettes, so that a distinct pubescent area is formed ; the intermediate 
tarsi are rather slender, and the three basal joints bear beneath an elongate sexual 
pubescence, and on the fourth joint there is a less conspicuous development of such 
pubescence. The female has usually a distinct though not extensive sexual sculp- 
ture on the base of the elytra ; this sculpture consists of elongate punctures, which 
at the extreme base extend from the scutellum to quite near the lateral margin, 
they do not extend, however, more than one-third of the way to the apex, diverge 
greatly from the suture as they proceed, and also to a less extent from the lateral 
margin. On the hind tarsi of the male the inner claw is quite as long as, or even 
longer than, the outer one, while in the female this inner claw remains rudimentary, 
and is only to be perceived by examining the undersurface of the other claw, to which 
this rudimentary one remains closely applied. 
This species is variable, but. it is possible that some of what I have considered 
TRANS. ROY. DUB. SOC., N.S., VOL. II. 4Y 
