Note:
Beam trawls used in the Transect Program do not adequately
collect burrowing organisms,
so the distribution and abundance of this species is not well documented.
This large irregular
urchin has 5 characteristic notches and only one lunule on the posterior end
(lower half
of the photos). The posterior edge is nearly straight. Test length (height)
is ~ 10 cm.
Many specimens were collected from a dredge in the mid-shelf region.
These organisms
live as infauna (living beneath the sediment surface), and are not often collected
using surface beam trawls. All specimens were returned to the sea.