Rapp beach find

[Rowboater]

Picked this up on the beach. @abyssunder suggested an earlier piece might be tabular coral.  This is quite different, but similarly like a hard rock,but with arrays of aligned tubes, some broken or missing.  Not something I see often here!   First two photos are of the same side, with a broken shark tooth holding the surface more flat.  Scale is in cm. Hopefully someone recognizes it and can guess an ID.  Thanks. 

 

[Rockwood]

Could be a favositid alright.

It's tabulate coral, by the way. 

[abyssunder]

It's a tabulate coral, in my thinking.

[Rowboater]

@abyssunder @Rockwood  Thanks for the ID! 

It's a bit weird, most of the stuff I find on the beach is Miocene (or even more recent) and this is the second small one of these I've found this year (probably two different species by their appearance), at least ten times older according to what I've read?  Geological maps show Devonian fossils 100 miles up river, so I guess that could be the source?  More likely (to me anyway) there is a small amount of older material outcropping nearby?   A third alternative: maybe ballast rock from boats in the 17th thru 19th century?  There are rock piles in the river nearby from the ships unloading their ballast so they could travel up the shallow river.