In his "Monograph of the British Stromatoporoids," Prof. H.A. Nicholson said, "so far as known Amphipora is represented by one species only, viz.: the form described by Phillips under the name of Caunopora ramosa (Fig. and Descript. Pal. Foss., p. 19.) This remarkable species occurs in vast numbers in the Devonian rocks of Germany and Devonshire, apparently occupying in the former region, as probable in the latter also, a definite horizon in the upper portion of the Middle Devonian series (the Ramosa-Bänke of Schulz)."