456 THE DISTRIBUTION OF CALIFORNIAN MOTHS. 
ence, and of Mr. Lesquereux’ able papers in Hayden’s Geological 
Reports on the Territories, 1872. The main features in the geo- 
graphical distribution of land animals are apparently the same with 
those of plants. Prof. Gray shows that ‘almost every character- 
istic form in the vegetation of the Atlantic States is wanting in 
California, and the characteristic plants and trees of California 
are wanting here” (i. e., in the Atlantic States). We may on the 
whole say of thé Californian Lepidoptera, at least, as Dr. Gray re- 
marks of the plants, that they are “as different from [those] of 
the eastern Asiatic region (Japan, China and Mandchuria) as they 
are from those of Atlantic North America. Their near relatives, 
when they have any in other lands, are mostly southward, on the 
Mexican plateau. . . . The same may be said of the [insects] of 
the intervening great plains, except that northward and in the 
subsaline [insects* ] there are some close alliances with the [in- 
sects] of the steppes of Siberia. And along the crests of high 
mountain ranges the arctic-alpine [insect-fauna] has sent south- 
ward more or less numerous representatives through the whole 
length of the country” (p. 10). He then refers to the ‘“ astonish- 
ing similarity” of the flora of the Atlantic United States with that 
of northeastern Asia. Our actual knowledge of the insect spe- 
cies of northeastern Asia is most vague compared with the exact 
knowledge of the botanist, and the comparison we have drawn 
. relates only to generic types. 
e It is evident that the notion of continental bridges in quater- 
. nary times, connecting for example Asia and California, is quite 
unnecessary, since there are, so far as is yet known, no forms 
characteristic of Asia in the Californian fauna, and the grand diffi- 
culty is to account for the presence of a certain resemblance to 
* Dr. Leconte has noticed’ the simil arity of our saline-plains beetles, oe ee s0 
many species of Tenebrionidæ, to the fauna of the deserts and steppes of Asi . (Proc: 
Sci., 1851. Alb 
er x 
graphical Relations 08 Rg chief Contam ese p. 36, 1871) also refers to this 
fact; genus El H ds: 
tirps than perhaps occurs east of the Rocky Mountains.” = 
Mr. Murray in explaining the term m ee, states that “the fauna ap 
yl ts type and standard.” 
