Correlations between mean values of tail length in respective local populations of Dymecodon pilirostris and medial latitudes of localities of the latters revealed the presence of two distinct linear clines among them (Fig. 2) . The mean values of tail length in respective populations belonging to the clines can then be expressed by a formula Y_c=a+bX. As 'a' and 'b' remain always constant in any population within a cline, it may be reasonable to conclude that such populations differ one another only phenetically at least in this character and may constitute a single taxon as there are no other differences discovered among them. The 'a' and 'b' values, however, are evidently different in accordance with clines and probably with degrees of evolution of the group. So that a cline of this kind seems to represent a 'lineage' of the author's concept which is equivalent both to the species and subspecies of the most of authors. A specimen recently discovered by the Crown Prince of Japan from Mt. Asama, Central Honshu, obviously belongs to the lineage B composed by Shiga, Nikko, Zao, Goyo and Hayachine populations. This lineage is characterized by relatively shorter then probaly more progressed tail than that of the lineage A which contains populations from Fuji, Minami Alps, Chichibu, Yatsugatake and Kita Alps and has relatively longer and primitive tail.