Australian, subdivisions of, i. 77
Neotropical, defined, i. 78
Neotropical, subdivisions of, i. 78
Nearctic, defined, i. 79
Nearctic, distinct from Palæarctic, i. 79
Nearctic, subdivisions of, i. 80
Regions, zoological, i. 50
zoological, how they should be formed, i. 53
zoological, may be defined by negative or positive characters, i. 54
zoological, by what class of animals best determined, i. 56