I still have trouble when trying to catalog biology books, such as the one I currently have in hand, on migration of sea lions. Please advise.

First, pay close attention to what it says in the Manual at the entry for 570-590:

"The main point to remember in classifying works that treat both a specific biological subject and a specific kind of organism is that the subject takes precedence in 571-575 (the span devoted to internal processes and structures), while the organism takes precedence in the rest of biology. Comprehensive works on subjects other than internal processes and structures are classed in 576-578, while works on these other subjects limited to specific kinds of organisms are classed with the kind of organism in 579-590."

In other words, if the work is about a plant, animal, or organism behavior or process that can be witnessed by a biologist in the field, it is placed under in 579-590, whereas if it is about an internal process--often something that is viewed under a microscope in the laboratory--it is placed under 571-575.

General works on animal migration are classed in 591.568. Because the topic does not fall in the span 571-575, you expect that the base number used for building a number for sea lion migration will be the number for sea lions. (Moreover, if you look at the add note for 591.568, you see that it provides only for adding standard subdivisions, not specific type of animal.)

The number for sea lions is 599.7975, at which there is a note that says, "Add as instructed under 592-599." Under "General topics of natural history of animals" in the build table at 592-599 it says, "Add to base number 1 the numbers following 591 in 591.3-591.7, e.g., beneficial animals 163, marine animals 177."

The number for a work on sea lion migration is, therefore, 599.79751568: 599.7975 (sea lions) + 1 (from 592-599 General topics of natural history of animals) + 568 (animal migration).

Last revised: 18 November 2003