300 Capt. F. Balfour-Browne on 
From that time on the writers can be divided into those 
who regarded “ elegans” as a synonym of “ depressus””? and 
those who recognized two distinct species. Among the 
former are Schonherr, Gyllenhall, Kunzé, Stephens, Zetter- 
stedt, Wilson and Duncan, Aubé, Schiddte, Schaum (1868), 
and Sharp. 
So far as I can make out, Stephens has merely followed 
Kunzé, since in his later work (1829) he gives the species as 
“¢depressus, Kunzé.” Aubé regards individuals with the 
black reduced as elegans, Sturm, and his long description is 
mainly a colour one. Schaum, in an earlier paper (1848), 
regarded elegans as a distinct species, and he mentions its 
occurrence in salt lakes in Saxony, refers to the synonymy, 
and points out the longer form and darker underside of 
“ depressus, F., Gyll., Sahlb., 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), elegans being found throughout Mid and South 
Germany, France, and Switzerland. In 1868, however, he 
alters his opinion, giving “elegans” as a synonym of 
“ depressus,” but remarking that Swedish examples “ (77. de- 
pressus, Gyll.)”? are longer and darker than the German 
ones. 
Sharp, in his ‘ Dytiscidee,’ says nothing about elegans, and 
gives what is mainly a colour-description of ‘ Dytiscus 
depressus, Fab.” His types (no. 241. 1 g and 1 9 “ 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 find Sturm, Murray, Bach, Bosé, Seidlitz, Ganglbauer, 
Everts, and Reitter, while we may perhaps include the 
Sahlbergs 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 Schiddte, he admits 
that he has only seen a single specimen of the northern 
depressus, and lis descriptions, beyond referrig 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 pl. cciil. he has a typical elegans labelled 
“ H, depressus,’ which he explains is a mistake for “ H. 
brevis.” On pl. cev. he illustrates (A) 2. elegans, Llig.,”’ 
