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"Archaeocidaris Urii, Flem (spine and intermediate plate); Carboniferous, Ireland." — Encyclopedia Britannica, 1893

Fossil Echinidea

"Archaeocidaris Urii, Flem (spine and intermediate plate); Carboniferous, Ireland." — Encyclopedia…

"Hemicidaris intermedia, Flem.; Corallian, Calne." — Encyclopedia Britannica, 1893

Fossil Echinidea

"Hemicidaris intermedia, Flem.; Corallian, Calne." — Encyclopedia Britannica, 1893