Is Meta mengei Blackwall a variety of Meta segmentata (Clerck) ? (Aranei-Argiopidae)

Since 1870 it has been a matter of debate among araneologists whether Meta mengei, described by Blackwall in that year, and separated by him from Meta segmentata (Clerck, 1757), is a real species or only a variety. In order to find an answer to this question I give an historical survey of the views of the most important authors concerning this matter, followed by a discussion of the peculiarities generally regarded as characters distinguishing the two species or varieties, and a short account of my own investigations. 1757. Clerck figures and describes a species of spiders of which in the beginning of September he observed a great number ; he names it (Araneus) segmentatus. 1758. Linnaeus publishes a concise description of the same species and names it Aranea reticulata. Further synonyms are to be found in Roewer (1942, pp. 915-916). 1862. Next to Meta segmentata, Westring distinguishes a species named by him Meta albimacula (Koch?), because in his opinion it is identical with Koch's Zilla albimacula. 1866. To his elaborate notes on M. segmentata, Menge adds an appendix about "eine neue art oder abart" (a new species or variety), referring to Westring's M. albimacula. He proves that this species is not identical with Koch's Zilla albimacula ( = Zilla diodia Walckenaer), but he considers the differences from M. segmentata not sufficiently marked for a separate species and regards it as "eine kleinere abart" (a smaller variety). 1870. Blackwall, who in 1864 had given an account and a drawing of Epeira inclinata (= M. segmentate), now elaborately describes the "variety