Geisonoceras has an orthoconic shell with transverse lirae and striae that are periodically thickened.
Here is a very unique dish carved from Fossil Rock from Morocco. This lovely dish has a nice Geisonoceras fossil and very cool design with lots of visible fossils on the balance of the dish. It measures 5 1/2″ x 7/8″ with a nice polish. This would make a great gift or keep it for yourself!