There are three geographical subspecies: Sciurus griseus griseus (central Washington to the western Sierra Nevada in central California); S. g. nigripes (from south of San Francisco Bay to San Luis Obispo County, California; and S. g. anthonyi, which ranges from San Luis Obispo to northern Baja California).
Unity of command is ensuring unity of effort under one responsible person (or commander) for completing a task. This unity of command is one of the twelve principles of joint operations, and is defined as:
By unity of type is meant that fundamental agreement in structure, which we see in organic beings of the same class, and which is quite independent of their habits of life. On my theory, unity of type is explained by unity of descent.