300 Capt. F. Balfour-Biowne on 



From tliat time on the writers can be divided into those 

 who regarded " elegans" as a synonym of "dejyressus" and 

 tbose who recognized two distinct si)ecies. Among the 

 former are Sciionherr, Gyllenhall, Kunze, {Stephens, Zetter- 

 stedt, Wilson and Duncan, Aub^, Schiodte, Schaum (1868), 

 and Sharp, 



So far as I can make out, Stephens has merely followed 

 Kunze, since in his later work (1829) he gives the species as 

 " depressus, Kunz6." Aube regards individuals with the 

 black reduced as elegans, Sturm, and his long description is 

 mainly a colour one. Schaum, in an earlier paper (1843), 

 regarded elegans as a distinct species, and he mentions its 

 occurrence in salt lakes in Saxony, refers to the synonj'my, 

 and points out the longer form and darker underside of 

 '■'■depressus, F., Gyll., Sahib., and Sturm, and also refers to 

 the distribution of this latter species, which, he says, appears 

 to be indigenous to Finland, Sweden, Denmark, and Kief 

 (Mid-Russia), 6^/f^an5 being found throughout Mid and South 

 Grerniany, Frtmce, and Switzerland, in 18G8, however, he 

 alters his opiniun, giving " elegans ^^ as a synonym of 

 " depressus/' but remarking that Swedish examples " (H. de- 

 pi'esszis, Gyll.) " are longer and darker than the German 

 ones. 



Sharp, in his ' Dyliscidte,' says nothing about elegans, and 

 gives what is mainly a colour-description of " Dytiscus 

 depresstis, Fab." His types (no. 2-11. 1 cJ and 1 ^ " An- 

 glia" and 1 ? " Europa "), in the Natural History Museum, 

 are, however, our common species, and I have therefore 

 concluded that he regarded " elegans " as a synonym of 

 " depressus." 



Among those who regard elegans as a distinct species 

 we Hud Slurni, Murray, Bach, Bose, Seidlitz, Ganglbauer, 

 Everts, and Keitter, while we may perhaps include the 

 ^ahlbergs and Thomson, who only describe depressus, but 

 from a region where elegans would be less likely to occur. 



Sturm makes three species out of his material, calling his 

 new one " brevis" but, according to Schiodte, he admits 

 that he has only seen a single specimen of the northern 

 dep>ressus, and his descriptions, beyond referring to minute 

 differences in form, only deal with colour-characters. Subse- 

 quent authors have regarded his " brevis " as a synonym of 

 " elegans.'^ 



In his ' Icones ' on pi. cciii. he has a typical elegans labelled 

 "H. dep7'essus,'^ wliich he explains is a mistake for " ^. 

 brevis." On pL ccv. he illustrates ^' (A) U. elegans, Illig.," 



