On the Value of the “Neoarctic” as one of the Primary Zoological Regions

PERMIT me to make a few remarks relative to Mr. Wallace's criticisms (NATURE, vol. xxvii. p. 482) of my paper on ``The Value of the Neoarctic as one of the Primary Zoological Regions.'' Briefly stated, it is maintained in the early portion of this paper (1) that the Neoarctic' and Palæarctic faunas taken individually exhibit, in comparison with the other regional faunas (at least the Neotropical, Ethiopian, and Australian), a marked absence of positive distinguishing characters, a deficiency which in the mammalia extends to families, genera, and species, and one which, in the case of the Neoarctic region, also equally (or nearly so) distinguishes the reptilian and amphibian faunas; (2) that this deficiency is principally due to the circumstance that many groups of animals which would otherwise be peculiar to, or very characteristic of, one or other of the regions, are prevented from being such by reason of their being held in common by the two regions; and (3) that the Neoarctic and Palæarctic faunas taken collectively are more clearly defined from any or all of the other faunas than either the Neoarctic or Palæarctic taken individually.