On Aquatic Carnivorous Coleoptera or Dytiscide. 278 
is somewhat flattened or depressed, except at the extreme base; so that the sexes 
can only be distinguished by the structure of the tarsi. 
South America ; Amazons. (Pampas Germain). 503. 
The individual from the Pampas in M. de Bouvouloir’s collection is slightly larger and more convex, 
and elongate, but if a distinct species it must be a very closely allied one. 
45. Canthydrus brevicornis, n. sp.—Ovalis, convexus, nitidus, supra nigricans, 
capite thoracisque lateribus picescentibus, antennis fuscis, basi testaceo; corpore 
subtus anterius rufescente, posterius nigricante; elytris obsoletissime punctatis, 
seriebusque punctorum subdistinctis; prosterni processu canaliculato. Long. 2%, 
lat. 13 m.m. 
Closely allied to Hydrocanthus nigrinus (No. 47), but not half the size, and with 
the penultimate joints of the antenne much shorter. The only individual I have 
seen is I think a female, but has only an indistinct impression on each side of the 
apical ventral seoment. 
Brazil, (Parana). 502, 
46. Canthydrus rufipes, n.sp.—Ovalis,sat convexus et elongatus, pernitidus, picco- 
rufus, elytris nigricantibus, antennis testaceis; corpore subtus anterius rufo, posterius 
nigricante ; elytris seriebus duabus sub-distinctis punctorum. Long. 35, lat. 2 
m.m. 
Extremely similar to Hydrocanthus nigrinus (No. 47), but:rather less convex, a 
little paler in colour, and the prosternal process without channel. The female has 
the apical ventral segment impressed on each side. 
Cuba ; Amazons ; (Parana?) 501. 
47. Hydrocanthus nigrinus, Aubé, M.C.—Ovalis, convexus, sat elongatus, 
pernitidus, supra niger, capite thoraceque versus latera picescentibus, antennis fuscis, 
basi testaceo ; corpore subtus anterius rufescente posterius nigricante ; elytris serie 
punctorum distincta, preterea fere impunctatis; prosterni processu canaliculato. 
Long. 33, lat. 2 m. 
The female has a large impression on each side of the apical ventral segment, of 
which there is no trace in the male. 
South America; Bahia, (Antilles and Brazil fide Aubé). 500. 
48. Suphis lineatus, Horn, Tr. Am. Ent. Soc. 1871, p. 8329.—Ovalis, sat convexus, 
nitidus, rufescens, prothorace medio fusco; elytris sutura vittisque tribus latis 
(externa interrupta) nigris; elytris crebre sat fortiter punctatis. Long. 3, lat. 13 m.m. 
