40 
forgetting that all through the district they assume the same colour, 
though there are no rocks exposed, or blue lichen for them to copy, for 
miles around. Again, at Bridston Hill, in Cheshire, this species is a 
very black insect; this range of hills is white sandstone covered by 
ordinary heath plants.” Earlier ( Notes on Variety Manufacturing, p. 
7, Liverpool, November, 1878), the same writer had given a somewhat 
muddled paragraph, which I will quote verbatim.: “ Gnophos obscuraria 
on chalk lands is a light-coloured grey or drab insect. In carbonifer¬ 
ous limestone districts it is a lead-coloured insect, whilst on the new 
red sandstone, “ Keuper ” formation, it varies from a rich ochreous 
colour [sic] , where oxide of iron is present in the soil, to a dark, 
almost black insect, on the white sandstone parts of the new red forma¬ 
tion, thus clearly pointing to geologically-caused changes of colour, as 
Gnophos obscuraria feeds exclusively upon the same species of grass 
everywhere. Any of these latter forms, acted upon by chlorine, appear 
as light-coloured greys.” 
NOTES ON BREEDING G0N0D0NTIS B1DENTATA AB. NIGRA. 
(Read April 21st, 1903, by T. H. HAMLING.) 
The earliest notice of the appearance of this striking and interest¬ 
ing aberration has been given to me by Mr. G. S. Porritt, of Hudders¬ 
field. He informs me that it was first taken by a Mr. George Parkin, 
of Wakefield, at Wakefield, about the year 1890, and has been taken 
by him regularly since, but never in numbers. It was brought under 
the notice of Mr. Porritt in the year of 1892, and one of his specimens 
is figured in Barrett’s British Moths, vol. vii., on plate 289. Mr. J. T. 
Wigin, of Methley, Leeds, from whom my original stock of ova came, 
informs me that he first took this dark form at Methley (which is about 
six miles from Wakefield), during the spring of 1895, and has taken it 
each year since, but it occurs there very sparingly, he remarks that the 
type in the district is of a leaden hue, and that next to the black form, 
the yellow form is scarcest, I learn from Mr. S. Walker, of York, that 
this form also occurs in the Manchester district, large numbers of 
larvae having been taken, and odd black forms bred from them, whether 
it occurs regularly or not in the district, I am unable to say, but up to 
the present the only localities, as far as I have been able to ascertain, 
are Wakefield, Methley, and the Manchester district. It was brought 
under the notice of the Society during the year 1901, from specimens 
that I had bred, and Mr. L. B. Prout remarked that such a striking 
form ought to be named, and thus we find in the Ent. Record, vol. xiii., 
p. 336, the appropriate name of nigra affixed, for it is almost wholly 
black, with the transverse line a trifle paler, the thorax only retaining 
the colour of the type. This as a preface to my notes on breeding 
Gonodontis bulentata ab. nigra, I will now narrate with what success I 
did breed this interesting aberration. 
During the spring of 1900, my brother, who was corresponding and 
exchanging with Mr. J. T. Wigin, of Methley, was offered a batch of 
