Used an online key to find out its a type of coral, but I'd like to know more about it.
See how much wetting the rock helps show its features?
As you suggested (email, pers. comm.), Syringopora is a possibility.
To me it looks like Lithostrotion / Siphonodendron.
For reference re Lithostrotion:
- http://avonrigsoutcrop.blogspot.com/2012/06/lithostrotion.html (good close-up showing internal structure)
However, one's reaction in such things is biassed by what one happens to be familiar with. There are other candidate genera, but I have simply not come across them. I couldn't help you tell them apart; you'd really need a proper palaeontologist, preferably a coral expert. I hope one's looking-in.
In general, we'd like to know where you found it, geographically and geologically, as far as is possible. That could reduce the number of possible genera/species. In this case, I know you don't know; so OK.
This "water trick" really caught me by surprise ! :D
This fossil , along with the Bryozoa and crinoid, was found close to the wicklow mountains in Ireland. ( currently living in Ireland near the wicklow mountains but will be moving back to the uk this summer :) ).
Oh and my previous suggestion was a completely uneducated one. It was the only option in the online key.
So thanks for pointing out some other possibilities.
Ah, Wicklow, well that's good to know.
As it happens, I don't have useful knowledge of Wicklow re fossils, sorry.
Yes, wetting a stone can make a great improvement to seeing what it contains.
But polishing can be even better.
You can polish all the way to a glass-smooth finish, or polish most of the way then apply varnish. The former takes longer, the latter is quicker and in some cases (on soft rocks) necessary.
The following shows both rock polishing and an example Siphonodendron...
Have a look at tqb's stunning photos and specimen showing Siphonodendron junceum in magnificent detail and clarity. He doesn't say so, but he has polished a corner of the stone.
This sort of transformation from knobbly nothingness to high-def full-colour (crickey, even a bit of 3D) viewing can get you hooked on collecting rocks (for minerals and structure as well as fossils). ...Which, with some folks, can lead to a whole career.
Obviously tqb has great photographic technique, too. To get such good close-ups, you need proper macro facility (various ways to achieve it), awareness of lighting, use of tripod and delayed/remote shutter release, and good specimen preparation.