for in some cases not one species is identically the same, but they belong to the same families, genera, and sections of genera, and sometimes are similarly characterised in such trifling points as mere superficial sculpture.
Gainera, Europako kretazikoan aurkitzen ez diren, baina formazioen goi edo behealdean ageri diren beste forma batzuk, ordena berean ageri dira munduko hain toki urrunotan.