The cowrie oracle is not equally placed in the two halves of its history, and Bascom's 1980 comparison is direct about it. In Nigeria the sixteen cowries, erindinlogun, are the simpler oracle and stand in less esteem than Ifa, which is read by babalawos. In the Americas the relationship is reversed in practice: the cowries are more widely known and far more frequently cast than Ifa, because the priesthood that reads them is much larger.
That inversion is a fact about the two communities rather than about the oracle. It follows from who is initiated to what: priests and priestesses of any orisha may come to read the shells, whereas reading Ifa depends on initiation to Orunmila specifically.
It also explains a pattern a reader will notice in the literature. The Cuban material is comparatively rich on the cowries and the Nigerian material comparatively rich on Ifa, so a comparison between the two systems is partly a comparison between two differently weighted archives.
Ogunda, the three-mouth throw, carries a name shared with the corresponding figure in the Ifa corpus. Its proverbs, myth narratives and prescribed remedies are transmitted within initiated Lucumi practice.