“Ridges run forwards from the rhinophores to the front of the head” (Eliot, 1910) are shown on his image (1) and more prominently, but less accurately (2), in the original species description by Quatrefages (1844) who called them thick ridges, crêtes épaisses”. Roginskaya (2000), opined that Quatrefages’ image was of an abnormal specimen.

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