656 On Aquatic Carniworous Coleoptera or Dytiscide. 
The species is variable in colour, size, and form; the lateral and apical parts of 
the elytra are more or less dotted with black in the yellow colour, and this is more 
conspicuously the case when the yellow is extensive ; the apical portion is generally 
very largely yellow ; the black marks at the base and front margin of the thorax 
are generally united along the middle. 
South America, (Guatemala, Panama, Cayenne, Amazonia). 1027. 
1020. Hydaticus goryi, Aubé, Spec. p. 175.—Statura signaturisque variabilis ; 
capite thoraceque rufis, illo vertice et inter oculos, hoc in disco et in medio ad basin 
nigris ; elytris nigris, margine externo, fascia pone basin signaturisque pone medium 
versus latera ssepe longitudinaliter disintegratis, testaceis ; subtus piceus, antennis 
pedibusque anterioribus rufis; tarsorum posticorum ciliarum margine anteriore 
leviter arcuato, nullo modo angulato. Long, 143, lat. 83 m.m. 
This is very closely allied to H. pacificus, and like it shows a very interesting 
(but different) series of variations ; perhaps it may be connected with H. pacificus, 
when specimens from other localities are examined, but at present it should be 
treated as distinct; on the thorax there is a development of the black colour on the 
disc rather than on the anterior margin, and when there is a dark spot on the front 
margin the discal cloud is largely developed in the transverse direction: on the 
lateral portions of the elytra the coloration is generally greatly broken up into dots 
or lines, and the ciliz on the hind margins of the joints of the posterior tarsi are so 
arranged that their front margin forms a regular curve , while in H. pacificus this 
curve in the middle stretches very much farther in the anterior direction so as even 
to assume a subangulated form. 
A very peculiar and distinct variety is found in the Moluccas, it is small, and the 
elytra while largely black have the black colour much disintegrated into lines of black 
dots, and there is a complete absence of the transverse band of yellow colour near 
the base, and there is little or no tendency to the formation of a transverse band 
or spots of yellow colour behind the middle, (var. moluccarum). 
Another peculiar variety occurs in Batchian, it is also small, the elytra are very 
largely black, and the yellow transverse bands on the wing cases are quite distinct, 
but are broken up by black dots and interruptions, (var. batchianensis). 
Australia; Malasia; New Caledonia; (Moreton Bay, Hunters River, Rockhampton). 1026. 
1021. Hydaticus bihamatus, Aubé, M.C,—Statura signaturisque variabilis ; 
capite thoraceque rufis, illo vertice et hoc in medio ad basin et ad apicem nigris ; 
elytris nigris, margine externo, linea transversa pone basin, guttula laterali pone 
medium (versus suturam plus minusve extensa, et plus minusve disintegrata) 
signaturaque minore subapicali testaceis; subtus piceus, antennis pedibusque 
