PACKAED.] ZOOLOGY MOTHS OF COLORADO. 547 



Lithostege triseriata (Colorado and California); L. rotundata (California); 

 Lobophora montanaia (Colorado); Euas])ilaies spinaiaria (Colorado); Pha- 

 siane Meadiana (Colorado); AcidaUa quinque-linearia (California and 

 Colorado); and Caulostoma occiduaria (Colorado and Oregon). Each of 

 these species have representatives which do not occur in Eastern North 

 America nor in Western Europe, i. e., on the Atlantic coast, but in 

 Central and Southern and Eastern Europe and Asia Minor, Turkey, and 

 Western Asia, but not in India or Eastern Asia, i. e., China or Japan," 

 so far as yet known. Now, to account for this community of generic 

 types in regions so remote, we must suppose that the nearly identical 

 general climatic features of those two areas favored the preservation of 

 these generic forms, which are almost exclusively north temperate, 

 and characteristic of broad, elevated j)lateaus in the interior of the 

 two continents. These forms are not of tropical origin, and I cannot 

 account for their origin otherwise than from an ancient arctic continent. 

 The fauna of the Eastern Atlantic States is, as regards the continent, a 

 littoral assemblage, and thus equivalent to the fauna of Eastern Asia 

 ( j. e., Japan and China and India), which occupies the region bordering 

 the Pacitic Ocean, W^hatever may be our theories regarding the origin 

 of these great zoological regions,* we have similar regions with analogous 

 (i. e., having the same generic) types in Asia and Europe combined, 

 dividing the north-temperate zone into six zoological (and probably 

 botanical) divisions, with analogous geological and meteorological fea- 

 tures ; and to account for closely similar features in moths inhabiting the 

 elevated i)lateaus of Colorado and California and Central Europe and 

 Asia, we can oul^^ sa.^that the similar climatic features of those regions 

 have inducejl their preservation there and extinction elsewhere, while 

 originally descended from a common stock, which had its origin to the 

 northward. I imagine that much the same continuity of life existed in 

 Mesozoic and Tertiary times in the ancestors of these north temperate 

 forms, as now exists in the circumpolar fauna, and that in fact this north- 

 temperate fauna of the globe was in Mesozoic and Tertiary times the 

 then circumpolar fauna. 



It will be seen by the present list how largely we have been able to 

 add to the range of circumpolar forms, by a glance at the tables ])re- 

 ceding. Those tables, wliich show how limited is the distribution of the 

 moths there mentioned in alpine regions south of the polar regions of 

 America and Europe and Asia, which form small "islands" rising out' 

 of the north-temperate zone, evince the degree of change undergone 

 by the circumpolar fauna since the wane of the glacial period. It shows 

 the inadequacy of climatic causes within the present geological period 

 to account for the origin of any except varietal, and, in some cases, spe- 

 cific forms. Many of the forms, the study of which has led me to these 

 reflections, I have at first regarded as distinct species, and in some cases 

 described them as such, but I fully agree with Mr. Allen's practice of 

 uniting many so-called species, whenever we can find connecting links. 

 It is of the greatest importance to follow circumpolar and north-tem- 

 perate faunas around the globe, from continent to continent, with am|)le 

 means for comparison before us. It will then be seen how inadequate 

 must be our views of the geographical distribution of the animals and 

 I)lants of our own continent, without si)ecimens from analogous regions 

 in the same zone in the Old World. It will be found that for the study 

 of our insect-fauna of the Kocky Mountain and Pacific States we must 

 have ample collections from the Ural and Altai Mountains and sur- 



*The Eastern, Middle, and Western North ADiorican,a8 limited by Professor Baird 

 (Amer. Journ. Sv\, Jan., ItiGO, p. 5, G). 



