84 Gustav Häuser, 



than D. pandurus, as the Kuru-suwo, or warm streara of Japan runs up 

 the east coast, and the west has no such pleasant influence. 



Recently, in lat, 41°, I have taken a series of a species with the 

 head and thorax of a rieh coppery-red hue , and elytra green and partly 

 metallic. Finally , crossing the strait of Tsugar to the Island of Yezo, 

 we find D. rugipermis , another bright coloured species. Both the last 

 are near allies, and agree with T). Fortunei in general outline and form 

 of the tarsi. In the district of D. viridipennis , the new species, snow 

 lies on the length and breadth of the land three or four months in the 

 year , and there is frequently snow remaining on some of the higher 

 mountains throughout the summer, and a similar, though somewhat colder, 

 climate prevails in South-Yezo. The mean temperature in lat. 43° 3' 56'" N. 

 was, in January, 1878, at 7 a. m., 16° F., and in July, only 64°, and 

 August, 65°, and the depth of snow (mean), January, 11 inches , and 

 February, 48 inches. 



I am endeavouring to discover whetUer Damaster in any form exists 

 on the north-east coast, in lat. 44°, for there the Kuro-suwo leaves the 

 coast, and the sea in mild-winter is a mass of ice for two miles from the 

 shore, and, foUowing the rule of the others, a small highly coloured species 

 would occur here, if the genus extends so far. 



Thus we See in tracing Duinaster from the south to the north, species 

 become smaller, and step by step modified in form, with colour appearing 

 the higher we go, either in altitude or in latitude. In the mountains of 

 central Nipon, we have the blue D. pandunis, and in the north, metallic 

 species. The general change of contour and tarsal development are 

 divergences from the type easily explained by evolution , and, of course, 

 the cause of colour may be bracketed, too, under the same general laws. 

 In the south, the warm nights , with sumraers of tropical heat, are well 

 suited for the large, nocturna!, black-coloured species we find there ; but 

 the genus , in forcing its way north, must, as a warmth-loving creature, 

 accommodate itself to circumstances. Passing from the tropics, it becomes 

 either diurnal or crepuscular for it gradually enters the regions of twi- 

 light, and assumes the colours we naturally look for in diurnal insects. 

 D. pandurus in Yokohama come freely to sugar, and is well-known to 

 Lepidopterists there, as a nocturnal species, but of D. rugipcnnis I have 

 five examples taken at sap at five o'clock in the afternoon, and I have 

 more than once taken in crossing my path wbile the sun was well over 

 the horizon. 



In a wingless genus , such as the present, it is likely that some of 

 the larger islands may possess species peculiarly their own , and perhaps 

 D. Foriunci is oiie of these ; but in this case I should not look for. any 

 abnormal variety, but a species closely allied to that of the adjacent land. 

 There is no record at present, I believe , of two species iuhabiting the 

 same district." 



Später hat dann Lewis (1882) seine Beobachtungen nochmals 

 kurz zusammengefaßt, wobei er jedoch nichts Neues brachte, sondern 



