BRIEF [O.A.] Jensen, P... L... Author: Jensen, P... L... Recipient: Haeckel, Ernst Dating: 18.11.1877
BRIEF [O.A.] Jensen, P... L... Author: Jensen, P... L... Recipient: Haeckel, Ernst Dating: 02.12.1877
BRIEF OHNE UMSCHLAG Krabbe, Harald Author: Krabbe, Harald Recipient: Haeckel, Ernst Dating: 24.11.1877
BRIEF OHNE UMSCHLAG Steenstrup, Japetus Author: Steenstrup, Japetus Recipient: Haeckel, Ernst Dating: 07.12.1877
BRIEF MIT UMSCHLAG Lütken, Christian Author: Lütken, Christian Recipient: Haeckel, Ernst Corporation: Universitetets Zoologiske Museum Kjøbenhavn Dating: 07.12.1877