Packard.] 16 [May 7, 



while Boreus Californicus is more like the European B. liyemalis than 

 our two Atlantic species. 



The crustacean fauna of northeastern America, with Limulus as 

 its most remarkable feature, repeats that of eastern Asia; but on the 

 other hand Dr. Hagen states that the European genus Astacus oc- 

 curs in California, while Cambarus is only found east of the Rocky 

 Mountains. 



Mr. F. W. Putnam informs me that of one hundred and seventy- 

 three genera of fishes given by Giinther as inhabiting the seas about 

 Japan, only about thirty-six are represented on the northwestern 

 coast of America, and of these thirty-six the majority are also found 

 in the Atlantic, while about eighty others of the Japanese genera are 

 also represented on the southeastern coast of North America and in 

 the West Indian seas, of which a number are found on the western 

 coast of Central America as well. He also tells me that the fresh 

 water fishes of northern Asia, when compared with those of other 

 regions, more nearly resemble those of the northeastern parts of 

 North America, though a number of the genera are also common to 

 both North America and Europe. By the same authority I am in- 

 formed that there is a striking resemblance between the reptiles and 

 batrachians of northeastern Asia and northeastern America. 



My attention has been drawn to a consideration of these features 

 in the geographical distribution of animals by a perusal of the able 

 and suggestive essay by Prof. Gray on the distribution of Californian 

 plants, in his address at the Dubuque meeting (Aug., 1872) of the 

 American Association for the Advancement of Science, and of Mr. 

 Lesquereux' able papers in Hayden's Geological Reports on the Ter- 

 ritories, 1872. The main features in the geographical distribution of 

 land animals are apparently the same with those of plants. Prof. 

 Gray shows that " almost every characteristic 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 the Californian Lepidoptera, 

 at least, as Dr. Gray remarks of the plants, that they are " as differ- 

 ent 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 



