On Aquatic Carnivorous Cohoptera or Dytiscid(B. 611 



927. Rhantus remator, n. sp. — Ovalis, baud convexus, nitidus, subtus niger, 

 prosterno rufo, antennis pedihutque testaceis, pedibus posterioribus magis obscuris ; 

 supra testaceus, vertice nigro lufoque variegato, tborace in medio late transversitn 

 t'uscescetite, elytris crebre nigro-irroratis, tarsis posterioribus brevibus, articulo 

 quarto vix perspicue lobato-producto. Long. lOl, lat. 5i m.m. 



This species is excessively closelj'- allied to Djtiscus signatus, but I have not 

 been able to reduce the individuals I have seen of it to a variety thereof; the form 

 in the present species is broader in front, and the greatest width is nearer the 

 extremity of the elytra, and the black dots of the wing-cases are of larger size, the 

 thoracic dark mark is extensive, while in the broader varieties of Dytiscus signatus it 

 is always diminished ; the male characters are exceedingly similar, but the claws of 

 the middle and front feet appear a little thicker than in the corresponding sex of 

 Dytiscus signtitus; it is very probable however that this will prove to be only 

 another variety of that variable species. 



South America, (Peru). 876. 



928. Colymbetes vicinus, Aube, Rhantus vicinus, lU.C. — Ovalis, sat convexus, 

 nitidus, niger, supra testaceus, capite nigro anterius et in vertice testaceo, thorace 

 in medio vitta transversa nigra, basique plus minusve nigricante, elytris crebre 

 nigro-irroratis, antennis pedibusque rufis, illis extrorsum, et femoribus prsesertim 

 posterioribus, infuscatis ; tarsis posterioribus baud brevibus, articulo 4° gracili 

 brevius lobato-producto, unguiculo interne quam externo duplo longiore. Long. 

 9f, lat. 5 m.m. 



The male has the basal joints of the front and middle tarsi a good deal in- 

 crassate and compressed, and clothed beneath with moderately small palettes ; the 

 front claws are unequal, the anterior being moderately long, and rather thick, 

 with well marked basal lobe, the hind one a good deal longer, and thickened 

 between the base and middle : the claws of the middle feet are thick beneath and 

 rather short and nearly equal : the female often has the thorax very deeply sinuate 

 at the sides close to the front angles. 



South America, (Columbia). 877. 



929. Rhantus advena, n. sp.— (Jvalis, sat angustus, baud convexus, nitidus, subtus 

 niger, prosterno in medio piceo, supra testaceus, capite nigro-rufoque variegato, 

 thorace in medio vitta transversa nigra, basique nigricante, elytris creberrime nigro 

 irroratis, antennis testaceis articulo ultimo infuscato, pedibus rufis, femoribus infus- 

 catis ; tarsis posterioribus baud brevibus, articulo 4° gracili posterius lobato-producto, 

 unguiculis parum elongatis, crassiusculis, interno quam externo baud duplo longiore. 

 Long. 10, lat. 5 m.m. 



TRANS. ROT. DUB. SOC, N.S., VOL. II. ' * ^ 



