Jan., 1921 SUPPOSED TWO RACES OF LONG-BILLED CURLEW 27 
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overlap when extremes are considered. The Morro series will be seen to fall into 
an intermediate position as to males, the average and mode both a little closer 
to that of americanus; while as to females it falls unequivocally with ameri- 
canus. 
As to culmen.—The shortness of the bill in occidentalis as compared with 
americanus is the feature of difference which has been emphasized most. It will 
be seen that this difference varies from 16 to 33 percent, on the basis of the 
smaller, according to sex and measurer. The amount of overlapping of extremes 
is small, even lacking in the case of Oberholser’s figures for females (though 
here, it will be noted, only three individuals of each race were measured). The 
Morro males average almost exactly between the averages for americanus and 
those for occidentalis; the greater number of individuals, however, are grouped 
below the minima for americanus and nearer the average for occidental’s. 
The Morro females are also intermediate, the average a trifle nearer americanus, 
but the mode preponderantly nearer occidentalis. Most clearly, there are not two 
modes so that a person could say definitely that part of the individuals fall with 
americanus and part with occidentalis. 
Conclusions.—The effort to identify the fifteen examples of Long-billed 
Surlew from Morro with one or the other of the two supposed races fails abso- 
lutely. There are no color features whatever to go by; and as to average of all 
measurements the series in question falls into an intermediate position. Yet in- 
dividual variation is so great that extremes, in one respect or another, of both 
““americanus’’ and ‘‘occidentalis’’ are included. Because of the lack of any 
grouping of individuals near these extremes it is impossible to allocate the speci- 
mens under one head or the other. This fact militates against the hypothesis 
that both of the supposed races are represented. 
Another hypothesis to be considered here is that the Morro birds, being mi- 
grants, are from a breeding ground of intermediate geographic position, so that 
the characters are of intermediate average and the individual variation of wide 
range and bringing ‘‘mosaic’’ behavior of characters. But the measurements of 
breeding birds so far published are so very few and the manner in which they 
are presented so unsatisfactory that nothing conclusive can be inferred on this 
score. 
While the evidence presented by Oberholser and Ridgway points toward a 
tendency of northern bred Long-billed Curlew to be smaller than southern bred 
birds, the present writer is unconvinced that the amount of this tendency is great 
enough to warrant recognition in nomenclature. He proposes, therefore, that, at 
least until a more thorough demonstration to the contrary is forthcoming, the 
name Numenius americanus, without any subspecifie divisions, be employed as 
designation for not only all the Long-billed Curlew of California, but for ail 
those of North America. 
The reader is invited to study the accompanying actual-size graphs and see 
what conclusions he will come to independently. 
Berkeley, California, December 8, 1920. 
