6 PACIFIC COAST AVIFAUNA No. 11 
An example of how he had wished to undertake such a treatment is to be found 
in his paper on the ‘‘Distribution of the Mockingbird in California’’ (Auk, 
xxvill, 1911, pp. 293-300, map). Part of the trouble lies in the general lack of 
accurate systematic analyses of the variable groups of birds. Systematic ornith- 
ology is popularly supposed to have reached such a high plane that no further 
work remains to be done. As a matter of fact, the status of very many forms, 
both species and subspecies, is but imperfectly understood, and consequently it is 
impossible to map their distribution accurately. The type of work needed in 
this connection is well illustrated in Swarth’s paper entitled ‘‘The California 
Forms of the Genus Psaltriparus’’? (Auk, xxxi, 1914, pp. 499-526, pl. xu). A 
score of other groups demand similar close attention. 
There is marked need for much further field work, such as any conscien- 
tious student of birds can engage in locally, whereby relative numbers of each 
species will be ascertained for restricted areas throughout the year. The census 
idea is an excellent one in this connection, and it is to be hoped that greatly 
improved methods of recording bird populations will be developed, so that dis- 
tributional behavior can be expressed in more nearly exact terms than is at pres- 
ent possible. 
In the main list comprising the bulk of the present paper, the author has 
exercised care in admitting little known species to full standing. Where, after 
due enquiry, grounds have been found for doubting the validity of a record, it 
has been relegated to the Hypothetical List as a species credited to California 
on unsatisfactory grounds (see p. 173), or else the name appears under the 
synonymy of some other form, or sometimes both dispositions have been made 
of the doubtful record. With rare, so-called ‘‘accidental’’, species, the bird 
must, as a rule, have been secured and preserved in some accessible collection 
so as to be subject to re-identification whenever desirable. The oft-repeated 
maxim holds: That the more unusual and hence unexpected the alleged oceur- 
rence of a species, the better must be the evidence in the case; such evidence must 
be reasonably conclusive to warrant its acceptance as authentic. 
