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I.—Notes on new or imperfectly known Chalk Polyzoa

Published online by Cambridge University Press:  01 May 2009

Extract

A developmental sequence of Membraniporellæ showing progressive subordination of the ribbed front wall to a solid secondary front wall can be traced fairly directly from Membraniporella pustulosa, Bryd., which is prevalent in the zone of M. cor-anguinum and the Uintaerinus band and seems to die out in the zone of Marsupites. In the zone (restricted) of A. quadratus it is succeeded by

Membraniporella thoraciformis, sp. nov. (PL IX, Figs. 1–3.)

Zoarium unilaminate, incrusting.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1917

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References

page 145 note 1 Geol. Mag., 1910, p. 483, Pl. XXXVI, Fig. 9.Google Scholar

page 147 note 1 Geol. Mag., 1909, p. 398, Pl. XXII, Figs. 4, 5.Google Scholar