Fusulinid faunas from various locations spread throughout the Cantabrian mountains are described as belonging to about 180 species including 17 new species and 11 new subspecies of 18 genera. The latter are Staffella (with 3 new species), Parastaffella (with 3 new species and 2 new subspecies), Millerella, Ozawainella (with 2 new species), Pseudostaffella, Schubertella, Fusiella, Profusulinella (with 1 new species and 3 new subspecies), Aljutovella (with 1 new species), Hemifusulina, Beedeina (with 1 new species and 1 new subspecies), Verella, Eofusulina (with 1 new species), Fusulina (with 2 new species and 1 new subspecies), Hidaella (with 1 new subspecies), Fusulinella (with 3 new species and 3 new subspecies), Obsoletes and Protriticites. The faunas are closely comparable with those of the Eurasian continent, notably of Russia; not only in the species and genera but also in their chronological sequence. The assemblage zones have been subdivided into subzones and subdivisions: Assemblage Zones Protriticites Fusulinella Profusulinella Millerella Subzones B A B A Ps. antiqua Subdivisions B3 B2 B1 The subdivisions and subzones are considered to be only significant for this region where they have facilitated the correlation of many sections. These correlations have been almost invariably confirmed by Racz from his studies of algal floras, and have enabled a synthesis of the general sedimentary history of the Carboniferous Period here. The correlation of the NW European and Russian stages through the Donetz Basin, presented at Heerlen in 1958 is different from that derived from the Spanish floras and faunas. Despite shortcomings in some stratigraphic data the palaeontological identifications are valid and the difference in correlations must be considered significant. This forces the conclusion that some process possibly that of different rates of evolution, existed during this time.