3124 THE ZooLoGist—JULy, 1872. 
specimen which could be appropriately described as snow-white, but I do 
observe differences both in colour and size in our English insects. These 
differences, however, do not serve to distinguish latipennis (Hansoni) from 
niveus (Garnonsii), but are common to both forms; the English latipennis 
exhibits as great a range of variation, both in size and colour, as the English 
niveus; specimens from Cheshunt are precisely like those sent by 
Staudinger, and of the uniform dull tint depicted by Herrich-Schaffer, 
whilst others from Hampstead are of lighter hue and prettily mottled, or 
flushed with deeper brown. The important point is; undoubtedly, the 
broader rounder wing of A. latipennis, and although the winged females 
agree well with one another, from whatever locality they come, there 
certainly is a difference in the shape of the wings of the male, which is very 
perceptible when the narrowest and the broadest winged specimens are 
contrasted; and some of the Hampstead examples are larger insects, and 
have even broader wings than the Continental latipennis, differing in this 
respect as much from latipennis as the latter does from niveus. But other 
males captured at the same time and place, and specimens taken elsewhere 
consorting with amply-winged females, exhibit the narrower wing which is 
supposed to distinguish niveus; and, in fact, there is every gradation, the 
extremes may be connected by intermediate forms, and I do not think the 
breadth of wing can be depended upon as a test of their specific distinctness. 
“Tf this be so, I submit that there is, after all, but one species of 
Acentropus; with a wide European range, and exhibiting perhaps slight 
modifications in different localities, but gradual modifications, the extreme 
forms being connected by intermediate links. Its geographical range 
extends from about 4° W. to 45° E. longitude, and from 48° to 61° N. 
latitude ; even those who advocate the separation into several species admit 
that A. Neve ranges from the Gulf of Bothnia to the Bodensee, whilst A. 
latipennis occurs alike in England and South-Eastern Russia. And indeed 
with the exception of the isolated Sarepta, on the Volga, there is a continuity 
about the localities which favours the idea of the unity of the species; thus 
starting from St. Petersburg, we pass along the North coast of the Gulf of 
Finland, then along the Prussian Shore of the Baltic, and inland to Frank- 
fort-on-the-Oder, then to Holland, England, France, and the southernmost 
parts of Baden or the northern confines of Switzerland. The insect is 
so insignificant in appearance that it may well be overlooked; if searched 
for, I have no doubt it would be found wherever a pond-weed grows.”— 
P. 149. 
In conclusion, I may state that, although I do not conscientiously 
believe Mr. Dunning has settled the place of Acentropus in either 
a natural or an artificial system, yet I do think, and I feel sure that 
all entomologists will agree with me, that he has produced one of 
