Scientific name:Spirorbis borealis

Common name:sinistral spiral tubeworm

Location:Found in intertidalzone at East point, Nahant, MA, United States

Distinguishing feature: very small, unridged, off-white, calcareous tube. This is about five millimetres in diameter and forms a flat, clockwise spiral coil as seen from above. The worm retreats into its tube when above water but under water can be seen to have green tentacles