Remark: introduction (= part 2) signed June 1876; title page dated 1876; first part mentioned in Börsenblatt Nr. 283 (7 December 1875) page 4533 (“20 Novbr. 1875” mentioned) and 1875 mentioned on the wrapper (Figure 5); second part mentioned in Nachrichtsblatt der Deutschen Malakozoologischen Gesellschaft 8(8/9): 110 (= August/September 1876) and Börsenblatt Nr. 106 (15 October 1876) page 1517. [Also known under the title Monographia Pneumonopomorum viventium. IV. Monographiae Auriculeorum. Pars II]