flattish; grey; patterned; numerous. Are there stress marks on these (picture 3)?
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I can see that damage there as in the painted topshells in the other observation. The only reason I didnt agree your ID above is because I also see these seemingly flattened versions of Grey Top Shell also on my local shores and they seem so significantly different in shape to the more peaked ones, I just dont know for certain that they are Gibbula cineraria? They look exactly like them but 'flattened'.
Thanks Cathal. I guess you see G.umbellicaris as a likely candidate and I'm up for it.
I will need to collect some more during the week and do some b'metrics perhaps.
I can't see it generating more agreements though.
It is much less common here - only one record from the Orkney Southern Isles and none where I found these (NBN)
Hi Derek, I think your shells above are much more like a flattened cineraria than a flattened umbilicalis to be honest. They might well be G. cineraria- I just dont know if the species comes in peaked and flat versions? They dont appear to be as boldly barred as umbilicalis nor as purple.
Im replying here in relation to what Ive said above. In the light of a very good link posted by Chris on Graham's recent observation, it seems clear that Gibbula cineraria does infact come in tall and flat versions. The linked page shows why. G. cineraria is quite flat spired when a juvenile and it becomes progressively taller as it matures. At least thats what Malcolm Storey's 5th photo of cineraria depicts:
This explains the smallness of all the very flat looking G. cineraria and the absence of flat versions of it as a mature mollusc.
I believe your pictures above show this very well- look how small those flat shells on the coin are compared to the mature shell beside the coin.
Yes Cathal, they may be indeed (I have assumed from the beginning, they are cineraria). But as I am trying to broadcast that it's more enlightening to get informed (and encouraging) comment than a definitive ID, I'm comfortable.
I will do some 'metrics tomorrow. I went to the Scapa shore just now (as you do!) but simply got embroiled in another wet mystery (Littorina viride!) "No such thing" I hear you shout but wait for my post!
Cineraria/grey has very narrow vertical 'stripes' but umbilicus/flat & Pennants fewer
C. Yep, my books concur but there is a lot of variation - not as much as in 'my' periwinkles here http://www.ispot.org.uk/node/325029.
They also seem to wear more heavily and that may account for a flatter appearance.
Thanks but, you know, as it's the first time I've offered TWO IDs, it is good viewing and reading for anyone else (other than about five of us!)
Thanks for the agreement too.
Lat/Lng: 59, -2.9
OS grid ref: HY483128
Common both Atlantic and North Sea shores.
These on Lamb Holm