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Hydrochelidon Naumann Naturgeschichte der Vgel Mitteleuropas. Weiflgelige Seeschwalbe Hydrochelidon fissipes Pall Sommerkleid Weissbrtige Seeschwalbe Hydrochelidon hybrida Pall Schwarze Seeschwalbe Hydrochelidon nigra Weibchen im Sommerkleid Mnnchen im Sommerkleid org page Naumann Naturgeschichte der Vgel Mitteleuropas XI Band