Pyura pallida spicules. The long ones are from the mantle, the short ones from the test.

Licence: 
Creative Commons Licence
Creator: 
Savigny, 1816
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith