Dear Carol:
In addition to the other postings on the heart urchin, Moira atropos
(Lamarck, 1816), the three references listed below all put this in the
Schizasteridae.  A fantastic picture of the species is pictured in
Hendler, et. al. on page 238.
The species is known from the Tertiary.  The grooves on the top of the
urchin are almost closed to keep sand out of the respiratory area.
Color is  gray to pale brown, some with a red horseshoe splotch in the
center.  Size to 2 1/2"   Range from Cape Hatteras to Bermuda to Sao
Paulo Brazil, depths to 1493'  The urchin burrows in soft muddy bottom
and feeds on subsurface deposits of organic material.  As the urchin
digs in the sand, according to Ruppert and Fox, the animal plasters a
stabilizing layer of mucus on the walls of the burrow.  The urchin
maintains the shaft with extensible tubelike feet, and as the animal
moves slowly through the mud, the same tube feet excavate new vertical
shafts.  It is preyed upon by the starfish Luidia clathrata and the
margate fish.
Three excellent references to Caribbean and southeastern U.S. sealife
are:
Hendler, Gordon, John. E. Miller, David L. Pawson, and Porter M. Kier.
Echinoderms of Florida and the Caribbean, Sea Stars, Sea Urchins and
Allies. Smithsonian Institution, Washington, D.C., 1995.
 
Ruppert, Edward E. and Richard S. Fox. Seashore Animals of the
Southeast. University of South Cariolina Press, Columbia, South
Carolina, 1988.
 
Voss, Gilbert L.  Seashore Life of the Caribbean.  E.A. Seemann
Publishing, Miami.  1976.
 
Hope this helps.
 
Alan Gettleman
Merritt Island, FL.
 
 
 
 
Goodman, Carol wrote:
 Would anyone be able to provide any information about
 this, particularly an author's name and the date it was named?  Any
 other information you could provide about this specimen would be
greatly
 appreciated.  Many thanks.
 
 
 
> Carol Goodman