Hypothetical species
A species which has been recorded in a particular geographical area, but whose occurrence there has not been substantiated by taking a specimen or a photograph. The development of modern optical aids and field identification techniques has enabled 'sight records' to become acceptable (provided an adequate description based on field notes is submitted to the appropriate rarities committee), but the term 'hypothetical species' is still used in North America.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver