Jurassic Oxford Clay find ID

[Ossicle]

I will do these over a few posts. The site is Jurassic Oxford Clay, Peterborough Member, c.163 ma at Yaxley in Cambridgeshire. 

 

Any help would be greatly appreciated! The scale is in mm.

 

The first I thought was Genicularia Vertebralis, but it looks a bit different from the others I've found, and has three distinct lines at the bottom of an unusually straight column.

[Ossicle]

The second I think could be an echinoid spine, because of the raised bumps.

[Ossicle]

The third I had two thoughts over - either crinoid related, or worm related.

 

[Ossicle]

And the last I have no clue, but it is bumpy.

[Ludwigia]

I think you're pretty well spot on with your ids, but the photos are unfortunately somewhat hazy.

[Myrmica]

I agree with the echnoid spines, and I agree that the third photo shows tube worm tubes.  Nice finds.