註釋 Recent stratigraphical and paleontological studies of early Lower Cretaceous rocks of the Sverdrup Basin have revealed the presence of several important obreal Valanginian ammonite faunas, some of which are closely related to those of Northwest Europe, England, European Russia, European Arctic and Northern Siberia. This paper is a final report describing those representatives of the subfamilies Polyptychitinae Spath 1924 and Simbirskitinae Spath 1924 known from the Valanginian rocks of the Sverdrup Basin, District of Franklin, Northwest Territories and redescribing the original material and types of closely related Polyptychitinae from the Lower Saxony Basin, Northwest Germany. The paper also evaluates the generic, taxonomic and stratigraphic relationships of the Polyptychitinae and Simbirskitinae in Northwest Germany with those of other regions of the Boreal Realm. 