Vol. 1 (1866) as Erster Jahresbericht des naturwissenschaftlichen Vereines zu Bremen
Vols. 2–12 (1871–1893) as Abhandlungen herausgegeben vom naturwissenschaftlichen Vereine zu Bremen
Vols. 13–25 (1894–1922) as Abhandlungen herausgegeben vom Naturwissenschaftlichen Verein zu Bremen
second title from vol. 26 onwards: Schriften der Bremer Wissenschaftlichen Gessellschaft Reihe B
Vols. 45. 2001/2005– as Abhandlungen des Naturwissenschaftlichen Vereins zu Bremen
Because IPNI and BPH did not and still do not abbreviate "Verein" ("society", "club", "association"), this has two different abbreviation in IPNI: (1) and (2) are grouped with "Vereine" while three is under "Verein" and the publication is not acknowledged at all past 1926 (!!). Treating these as all separate seems counterproductive.