408 Rev. H. Clark on the Dytiscidoe 



Var. A with the longitudinal markings on the elytra entirely oblite- 

 rated, at the shoulders and on the apex alone being found any trace 

 of flavo-testaceous. 



//. hamatus at first sight abundantly differs from H. Hoivittii : the 

 broad transverse markings of the latter contrast evidently with the 

 longitudinal bands of the former ; there are, however, examples 

 before me which show that these differences of colour must not be 

 regarded as constant. I think that if. hamatus will always be found 

 to be perceptibly broader in form, not quite so parallel, and that the 

 punctures on the elytra are more distinct and not so closely arranged. 

 The two species may be separated from H. Gardnerii by the presence 

 of a medial obsolete stria on the elytra, which in the latter species 

 is entirely wanting. 



A common insect in the neighbourhood of Melbourne. In the 

 collections of the British Museum, Mr. Bake well, Mr. "Waterhousc, 

 and the Kev. H. Clark. 



3. H. Gardnerii, n. sp. 



H. ovatus, latus, impubescens, punctatus, rufo-fuscus ; thorace rufo-flavo, 

 ad basin fusco ; elytris latis, punctatis, haud unistriatis, rufb-fuscis ; 

 pedibus et antennis rufo-flavis. 



Long. corp. 2f lin., lat. 1^ lin. 



Ovate, broad, impubescent, punctate, rufo-fuscous : head large ; near 

 the lower and inner margin of the eyes is an obsolete circular depres- 

 sion ; the surface is impunctate and rufo-flavous, the margins of the 

 eyes being fuscous: thorax transverse, the lateral margins gradually 

 constricted in front ; the surface is thickly punctate, more especially 

 near the anterior and posterior mai'gins ; in colour rufo-flavous, the base 

 and front being fuscous : elytra ovate, thicldy punctate throughout, 

 in colour dark fuscous, slightly suffused towards the shoulders with 

 flavo-fuscous : abdomen and underside rufo-fuscous : legs and antenna 

 flavous or rufo-flavous. 



H. Gardnerii at first sight closely resembles var. A of //. hamatus ; 

 it is, however, decidedly a shorter insect, and the elytra arc unmarked, 

 as in that species, by any medial stria. 



From the neighbourhood of Melbourne. 



4. H. intcrror/ationis, n. sp. 

 H. ovatus, depressus, punctatus, nigro-ferrugineus ; thorace fusco, 



lateribus rufo-flavis ; elytris flavo notatis. 

 Long. corp. 2 lin., lat. 1 lin. 



Ovate, somewhat depressed, finely and thickly punctate, black, more 

 or less marked with ferruginous : head impunctate, black, the an- 

 terior part flavo-fenuginous : thorax subdepressed at the base, where 



