736 On Aquatic Caniivorous Coleoptera or Dytiscidce. 



butislessbroad behind : it standsabout equally near to that species and to the Dytiscus 

 tripunctatus group of species: it is readily distinguished from D. rceselii by the lateral 

 bandof theelytrawhichissimilar to that of D.tripuuctatusand by the sexual characters, 

 the female having no swimming ciUa3 along the outer margin of the hind tarsi beneath, 

 and the male having a largely developed sexual pubescence on the intermediate tarsi 

 From C. asiaticus (No. 1 1 42), the species of the D. tripunctatus group to which it has 

 the most resemblance on account of the colour of its undersurface, it is readily 

 distinguished by the broader epipleura;, and the difierent sexual characters ; the 

 anterior tarsi of the male being large, and the female having sexual sculpture on the 



thorax. 



I have seen only a single pair of this interesting species ; the male was in 

 Castlenau's collection, labelled, " Cybister tibialis, Keich. Madagascar" ; the female 

 is in M. de Bonvouloir's collection and bore no other indication of locality than a 

 blue ticket on the pin. I have no doubt that Madagascar is the habitat. 



Madagascar. 1081. 



1151. Cybister pectoralis, n. sp. — Robustus, ovalis, convexus, sat latus, parum 

 nitidus, supra nigricans, capite anterius prothoraceque ad latera testaceis, elytris 

 vitta raaro-inali ad apicem angustissima ad basin lata (cum epipleuris) testacea ; 

 subtus fusco-piceus, coxis posterioribus externe macula parva testacea, metasterno 

 gibboso, laciniis impressis ; pedibus quatuor anterioribus testaceis, posterioribus 

 nigricantibus ; elytris transversim rugosulis, epipleuris versus apicem latis. Long. 

 23, lat. 13, alt. 8i m.m. 



The male has the front tarsi rather large, but their pubescent area on the under- 

 surface is small : the middle feet have the three basal joints furnished with very 

 lono- sexual hairs, their claws are rather long, but slender : the female has the 

 basal portion of the elytra covered with dense short scratches, which extend about 

 half way to the apex, but in their terminal portion are very obscure, the thorax is 

 nearly covered with short deep scratches so densely placed as to render the surface 

 ruo-ose, but they do not extend to the head, and indeed leave even the anterior 

 maro-in of the thorax (in front of the transverse series of punctures) smooth. 



This species is a most remarkable one, owang to the peculiar conformation of its 

 undersurface ; the metasternum in front is swollen or gibbous, and the breast of a 

 peculiar metallic colour along the middle ; the curved series of punctures which 

 runs parallel with the inner margin of the middle coxal cavities are peculiarly deep 

 and coarse. 



I have seen only a pair of this species, the male I purchased from a dealer about 

 twelve years ago wdth the locality India ; the female w^as in the collection of M. 

 Castlenau, labelled " India, Deccan." 



East India. 1082. 



