"One of the most essential tools in the continued study of the avifauna of the state is a reasonably complete and accurate check-list, revised from time to time as new information comes to light. In addition to its obvious value as a list of the birds known to occur in the state, with the general distribution, relative abundance, and seasonal status of each, it has the indirect and highly important function of pointing out matters which require special attention. This is sometimes done by including in a "hypothetical list" the names of birds whose presence in the state is probable but not yet certain, by indicating the lack of materials, of accurate identification, and of other reliable information where these deficiencies occur, and in other ways"--Page 3