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Biologische Untersuchungen TAF. IV . GUSTAF RETZIUS ber den Bau des Eies der Eohinodermen etc bidi unt xv Taf IV rJJ ' i' tt ' mm Wmmm Gez Retzius Repr und Druck von Ceclerquists Graf Sthl TAF IV Illustration XV biodiversitylibrary org title Frst Carl Magnus Retzius Gustaf Stach Wilhelm Biodiversity