Yes - gastropod.
you'll see they come in quite a range of shapes. The ones with the general shape of yours are in Calliostomatidae, Trochidae, and Turbinidae. Those are modern ones, but the same shapes occur in the fossil record, too.
Holes - where sedimentary grains have fallen out and/or been dissolved.
Hornsea fossils and fossil collecting
(no gastropods shown, as it happens, but of general interest)
The images on my computer are very distorted and I have to save them to 'my pictures' to view them correctly.
This seems to happen with the majority of images that I view - I do-not know why.
It's a gastropod and although your specimen is water worn I think it is from the Lower Jurassic - Lower Lias, and is called Bathratomaria sp
Originally from the North Yorkshire area.
From your description I'm going to guess that you are using an old version of Internet Explorer? Unfortunately, supporting old versions of IE is very problematic so I can only recommend that you either upgrade to the latest release (if you can), or use an alternative, more up-to-date browser such as Firefox, Chrome or Safari.
If you are using something other than Internet Explorer, we've found that some browser extensions can conflict with the display of the images on the page (e.g. AdBlock Plus), so try disabling your extensions to see if this is the source of the problem.
Hope that helps,
I have Safari on my I-Phone and my I-Pad but my desktop computer is probably 7 years old and I thought it's age and lack of up to date programme's was possibly the problem.
Once again thank you.