On Aquatic Carnivorous Coleoptera or Dytiscide. 489 
This species has the antenne rather long and slender; the punctuation of the 
upper surface is less than in the other species. I haveseen but a single individual. 
Cayenne, (coll. de Bonvouloir). 601. 
656. Celina angustata, Aubé, M.C.—Suboblonga, elongata, angustula, subdepressa, 
nitida, glabra, rufo-testacea, elytris paulo obscurioribus ; antennis sat elongatis ; 
prothorace paululum punctato; elytris sparsim, sat subtiliter punctatis, punctis 
apicem versus subtilioribus sed vix crebrioribus, stria discoidali sat distincta. Long. 
32, lat. 13 m.m. 
Mas, tarsis anterioribus et intermediis sat dilatatis ; tibiis intermediis curvatis, 
medio incisura parva, parte basali tenui, apical 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 
Chey. Pernambuco,” scarcely differs however except by its more castaneous colour, 
and slightly coarser punctuation of the elytra. so that I consider it only a variety 
of this species. 
South America, (Cayenne, Pernambuco) ; North America, (United States). 602. 
J. 43.—Genus METH LES. 
Seutellum concealed, base of thorax acuminate and produced in the middle. 
Front and middle tarsi five-jointed, subcylindrical, the basal joints being without 
dilatation, and without clothing beneath, the third not at all bilobed. Swimming 
legs very feeble ; extremity of body spinose. 
Three species are included in this distinct and peculiar 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 Celine. 
The species are found in tropical Africa, Madagascar, Mesopotamia, and Egypt. 
657. Methles spinosus, n. sp.—Rufescens, glaber, sat nitidus, capite thoraceque 
leevibus, elytris sparsim sat fortiter punctatis ; subtus fere impunctatus ; prothorace 
lateribus leviter rotundatis, angulis posterioribus obtuse rectis. Long. 3, lat. 14 m.m. 
Head large impunctate. Thorax impunctate, the base pointed in the middle, the 
hind angles closely applied to the shoulders of the elytra, the sides but slightly 
