Graptolites
http://www.premdesign.com/grapto.html

http://www.museum.vic.gov.au/prehistoric/time/graptolites.html

http://www.oum.ox.ac.uk/thezone/fossils/inverts/grapt.htm

http://www.graptolite.net/Graptolites/

http://en.wikipedia.org/wiki/Graptolite

http://www.earth.rochester.edu/ees207/Graptolites/caplangrap1.html