The species of the genus _Setina_ have Alpine forms which agree in possessing a characteristic extension of the black pigment to form radiating junctions between the spots on the wings. Speyer, who discussed the interrelations of these forms in detail,[22] lays stress on the absence of genuine transitional forms between _aurita_ and the variety _ramosa_. Both are mountain insects but _ramosa_ extends to levels higher than that at which _aurita_ ceases, which is about 4,000 feet. The two forms are often found flying together. Speyer says that his brother searched diligently for transitional forms at the level of overlapping, but found none, so that at least they may be regarded as rare. The variety _ramosa_ is not infrequent at much lower levels (_e. g._, Chiavenna, 1,020 feet; Reussthal, 1,500 feet) and extends as high as the permanent snows. In the British Museum collection, however, I have seen several that I should regard as transitional. Speyer perhaps would have classed as _ramosa_ all in which the spots of the central field were united, and it is by no means unlikely that breeding would prove such individuals to be heterozygous.[23] There can scarcely be a doubt that the distinction between _aurita_ and _ramosa_ is factorial, the radiate _ramosa_ probably having the factor for striping. In support of this view may be mentioned the observation of Boisduval,[24] respecting a gynandromorphous individual, which was _aurita_ male on one side, and _ramosa_ female on the other. Speyer makes another excellent comment. He points out that the simple notion that the radiation is a mere extension of pigmentation consequent on the climate of the higher levels, will not fit the facts very easily, because the size of the spots varies greatly in _aurita_ itself at any level, and lowland specimens may actually have more black confined to the spots alone than some _ramosa_ possess on spots and lines combined.[25] The two Salamanders, _S. maculosa_ and its Alpine form _atra_, might not improbably furnish evidence bearing on the same problem. The two are of course very distinct, not merely in colour (_maculosa_ being spotted with yellow or orange while _atra_ is entirely black) but also in the mode of reproduction, a feature to which reference will be made in the next chapter. I cannot, however, find any evidence as to the overlapping of the two forms. _S. atra_ occurs from about 3,000 feet or somewhat less, and reaches great elevations in the Eastern Alps, but I do not know if the two forms ever occur in the same localities. Leydig,[26] Boulenger,[27] and most modern authorities regard the two types as distinct species, but they are in any case closely allied, and it would be of interest to have exact knowledge of their geographical delimitations.