418 Rev. H. Clark on the Dytiscidae 



thickly punctate throughout, in colour rufo-flavous, the anterior and 

 posterior margins being narrowly fuscous black ; the posterior marking 

 consists sometimes of two submedial spots : elytra subdepressed, thickly 

 punctate, of a dull black colour, with the lateral margins and also six 

 small longitudinal markings (three on either side of the suture) flavous ; 

 the lateral margins, narrowly flavous continuously, are more broadly 

 marked by three longitudinal flavous maculae : legs and antenna: flavous. 



Of H. Hansardii I have seen only two examples, from the neigh- 

 bourhood of Moreton Bay. The small size of the species, with the 

 regularity of its pattern, sufficiently distinguishes it from those species 

 the pattern of which it approaches. 



21. H. Darwinii, Bab. (Trans. Ent. Soc. Lond. 1843, p. 13). 



H. oblong-ovate, punctate, ferruginous : thorax testaceous, with two 

 medial spots of fuscous : elytra with a minute tooth near the apex, black, 

 with four slender and interrupted testaceous lines on each elytron. 



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



The type of this species is in the cabinet of the Entomological 

 Society of London. Originally taken by Mr. Darwin at King George's 

 Sound, during the voyage of H.M. Ship Beagle. 



22. H. sinuatocollis, n. sp. 



H. ovatus, sat latus, baud parallelus, crebre punctatus, flavo-ferrugineus ; 

 thoracis lateribus marginatis, sinuatis; elytris crebre fusco maculatis. 



Long. corp. 1-1 } lin., lat. £ lin. 



Ovate, somewhat rounded at the sides ; subpubescent, thickly and 

 coarsely punctate, rufo-fuscous : head finely punctate, rufo-flavous, the 

 base and in some examples the margins of the eyes being fuscous : the 

 sides of the thorax have a remarkable sinuation, being excavated me- 

 dially or post-medially ; between the basal foveae is a well-defined 

 transverse channel, as in H. multimaadatus ; the surface is fusco-fla- 

 vous, the anterior margin, and more broadly the posterior margin, being 

 fuscous ; this basal marking extends (more or less broadly) medially to 

 the anterior margin, but is bounded laterally by the basal fovea? : the 

 elytra are somewhat rounded in form, thickly punctate ; the surface is 

 rufo- or flavo-fuscous, maculated with dark fuscous markings ; these 

 markings are sparingly distributed, though differing in different ex- 

 amples : legs and antennce rufo-flavous. 



Unquestionably specifically distinct from H.multimaculatus, though 

 at first sight possibly to be confounded with it ; it is more rounded 

 in form, the sinuation of the sides of the thorax is very striking and 

 unmistakable, and the markings of the elytra (though this is a far 



