1 32 [ June - 



that on the Continent these parts are sometimes dark (var. marginatus) , 

 but I suspect this to be erroneous, as to which see my remark under 

 G. stiff riani. In length it varies from 5 to over 7 mm., and there is a 

 corresponding difference in width from 2| to 31 mm. There is some 

 difference in the distinctness of the serial punctures near the scutellum ; 

 and the individuals in which these punctures are most distinct corres- 

 pond, I believe, to the " var. mergus " of the older authors. 



A really marked variation occurs in colour. Usually the upper 

 surface has metallic reflections, the scutellum being brassy or golden, 

 and the raised suture of the elytra behind it having a similar reflection, 

 but in a few individuals the colour of the upper surface, including the 

 scutellum and suture, is totally black. This variation occurs in its 

 most marked form only in the less punctate individuals, and these were 

 considered a distinct species by Suffrian and were treated by bim as the 

 true natator. In some of the black examples, a very fine strigation of 

 the surface can be detected, and these are no doubt the var. corpulentus, 

 Schatzmayr (Wien. ent. Zeit. xxii, p. 172). Intermediate examples 

 occur, and Suffrian subsequently changed his view, and united all as 

 one species. The extreme black form may be known as var. B, or as 

 var. corpulentus, Schatzm. Although the pronounced black coloration 

 occurs only in the natator (or slightly punctate form) yet there are 

 individuals of the mergus form that approximate this coloration. 



As regards " mergus " I find it impossible to reconcile the statements 

 of various authors, and there would be no practical result from fully 

 ting out the contradictions. But one point must be alluded to as 

 3 name has been recently reinstated as that of a distinct species, 

 jgimbart in 1883 described a G. wanJcowiczi as distinct from natator ; 

 in 1887 Seidlitz distinguished (or supposed he did) mergus from 

 natator, and suggested that wankowiczi, Reg., was this mergus. In 

 1891 Regimbart formally adopted this view, and thus mergus now 

 appears as a distinct species. I doubt both the distinctness and the 

 applicability of the name, and also that wankowiczi = mergus, Seidl. ; 

 but in the absence of Ahrens' type the question is not likely to be 

 settled, and Suffrian gave us to understand in 1842 (Stettin, ent. Zeit., 

 p. 235) that Ahrens' specimens were lost. Suffrian was in communi- 

 cation with Ahrens, and it would appear that they really relied on the 

 black colour as the distinguishing feature of natator. The remarks I 

 made in 1868 as to the characters of " mergus " and '• natator, 1 " as well 

 as to their local variation, were based on an imperfect knowledge, and 

 are to a large extent erroneous. 



