132 
THE ESSEX NATURALIST. 
this purpose that I sent you "the only Planorbis that Mr. S. had pronounced 
to be new, and that I had found in the Clacton deposit. 
The Clacton freshwater formation is highly interesting, regardless 
of new species being found therein. I should have thought not so much 
of the species that have been termed new had not the authority of Mr. 
S.'s name been attached to them. But I would ask, is all doubt removed 
respecting them ? On the Planorbis in particular, in the first instance' 
you and Mr. Wood were inclined to think that it was the “ mature state 
of Planorbis nitidus " Then you thought probably it might be the 
young of “ Segmentina lineata ” ; and the specimens in Mr. S.'s possession 
you state to be “ the young of Zonites, probably Z. cell aria.” In case 
that any mistake has arisen in this matter—which I begin to think has—- 
I would advise you to keep the shells till I come to Town, and we will then 
compare those which I sent you as P. helicoides with the same specimfnse) 
in Mr. S.'s hands. ** 
You mentioned long ago that I had sent the wrong shells, and if, 
when we compare them, there should be a difference, there will be an end 
of the matter ; but I maintain that the mistake (if any) is not mine. I 
sent the only P. of that species from Clacton which I possessed, and, 
which I took from the card that Mr. Sowerby had placed them on when he 
sent them to me, named as P. helicoides .2 
Stanway, Octr. 8th, 1842. 
I went to the Copford lucustrine (s c.) deposit this afternoon, to see how 
far I was correct when I told you the bed of peaty matter was in some 
places two feet below the surface. I saw many of the three-banded helix 
(H. hortensis), possessing all their animal matter, and their colours nearly 
faded. Thousands of shells in that state I could have obtained from this 
thin bed of black peaty matter, two feet below the surface. As I went 
on purpose, I measured the small section,! which probably you will under¬ 
stand by the rough sketch. 
Vegetable mould 
Yellow loam 
black peat 
Loam with 
chalk boulders 
But let it not be thought that there is two feet of loam and mould 
over the whole of the space occupied by black peat. The latter crops out 
and forms the surface over a considerable portion of the field. I submit 
this detail to you to explain away your objection to the recent appearance 
of the shells which you saw at my house from this deposit. But the next 
time I have the pleasure of your company at Stanway, I will take you 
to the place and you will then judge for yourself. 
I also beg to inform you that I ordered a barrel of oysters to be sent, 
as you directed, and they were sent accordingly on Tuesday last by the 
Norwich coach. 
2 There lias been divergence of opinion respecting the true status of Planorbis helicoides 
described by J. I). C. Sowerby in 1840, Mat>. Nat. Hist., Set. 2, vol. iv , pp. 197-201, and it 
is clear from these letters that the best course to adopt, since the type specimen is lost, is to 
consign the name to oblivion. 
3 On the outer side of this letter there is the drawing ®f a tomb bearing on its side the 
following inscription : — 
“ Back to back here we lie 
In one grave my wife and I: 
When the last trump the air shall fill 
If she gets up —I’ll lie still.” 
No information is vouchsafed as to the whereabouts of the tomb. 
4 John Brown's sketches and descriptions of local sections have been largely made use of 
in the Geol. Stir. Memoir on the “ Neighbourhood of Colchester” (sheet 48 S.VV.) 1880—Eu 
J ot 
/III I I I I I 
numerous shells 
