On Aquatic Carnivorous Coleoptera or Dijliscidce. 489 



This species has the anteante rather long and slender; the punctuation of the 

 upper surface is less than in the other species. I have seen but a single individual. 



Cayenne, (coll. de Bonvouloir). 601. 



65G. Celina angustata, Aube, M.C. — Suboblonga,elongata, angustula, subdepressa, 

 nitida, glabra, rufo-testacea, el3'tris paulo obscurioribus ; antennis sat elono-atis ; 

 prothorace paululum punctato ; elytris sparsini, sat subtiliter punctatis, punctis 

 apiceni versus subbilioribus sed vix crebrioribus, stria discoidali sat distincta. Lono-. 

 3f, lat. It m.m. 



Mas, tarsis anterioribus et intermediis sat dilatatis ; tibiis intermediis curvatis, 

 medio incisura parva, parte basali tenui, apicali lata. ' 



This species is smaller than any of the others, and has the prosternal process 

 distinctly narrower. I have seen but a single specimen in Dejean's collection ; an 

 individual in the collection of the Brussels Museum, labelled " Hyd. xantholoma 

 Chev. Pernambuco," .scarcely differs however except by its more castaneous colour, 

 and slightly coarser punctuation of the elytra, so tliat I consider it only a variety 

 of this species. ' 



South Americ;!, (Cayenne, Pernambuco) ; North America, (United Stat3s). 602. 



I. 43.— Genus MFAIILES. 



Scutellum concealed, base of thorax acuminate and pioduced in the middle. 

 Front and middle tarsi five-jointed, subcylindrical, the basal joints beino- without 

 dilatation, and without clothing beneath, the third not at all bilobed. Swimmino- 

 legs very feeble ; extremity of body s))inose. 



Three species are included in this di-stinct and peculinr genus ; they have the size 

 and form of small Hydropori ; but the body being acuminate or spinose at the apex, 

 they look still more like Celinje. 



The species are found in tropical Africa, Madagascar, Mesopotamia, and Eo-ypt. 



657. Methles spinosus, n. sp.— Eufescens, glaber, sat nitidus, capite thoraceque 

 lajvibus, elytris sparsim sat fortiter punctatis ; subtus fere impunctatus ; prothorace 

 lateribus leviter rotundatis, angulis posterioribus obtuse rectis. Long. 3, lat. 1 i m.m. 



Head large impunctate. Thorax impunctate, the base pointed in the middle, the 

 hind angles closely applied io the shoulders of the elytra, the sides but slio-jitlv 



