HOW BIRDS ARE NAMED 
7 
tion; for example, that of our Robin, Plcmesticus migratorius migra - 
torius (Linn.). The first account of this bird appears in Catesby (1731) 
and it was later classified by Linnaeus in the twelfth edition (1766) of his 
epoch-making “Systema Naturae” as T urdus migratorius. By this name 
the Robin or ‘ Migratory Thrush ’ was known for over one hundred 
years, when that finer discrimination, which has increasingly character- 
ized systematic ornithology, showed that the genus Turdus of Lin- 
naeus contained species which, in the light of this more modern view, 
were generically separable. The type of the genus having been deter- 
mined to be Turdus viscivorus Linn., the Mistle Thrush of Europe, 
the name Turdus was restricted to that bird and its congeneric allies, 
and the genus Merula of Leach was accepted for our Robin and the 
species with which it is generically related. The bird’s name then became 
Merula migratoria (Linn.), the termination of the specific name being 
changed from us to a in order that it might conform to the gender of 
the generic name with which it was associated; and the parentheses 
enclosing the abbreviation for the name of Linnaeus, indicating that 
while Linnaeus described the species migratoria , he did not place it in 
the genus Merula. 
Now, by one of those unfortunate coincidences which have done so 
much to create confusion in zoological nomenclature, it was discovered, 
in 1907, that the generic name Merula of Leach was ‘preoccupied’ by 
the Merula of Koch, proposed by the latter for a genus of Starlings, and, 
under the ruling of the ‘Law of Priority,’ the name Merula could there- 
fore no longer be applied to the Robin and its congeners, and the next 
available name proved to be Planesticus of Bonaparte. There the case 
stands, though it is by no means impossible that in some obscure pub- 
lication Planesticus itself may be found to be preoccupied or perhaps 
antedated by some other name proposed before that of Bonaparte. 
Such cases, however, are the inevitable result of the rigid enforcement 
of now universally accepted laws of zoological nomenclature, which, 
if they had been in existence and observed from the time of Linnaeus, 
would have prevented these seemingly unnecessary changes in the 
technical names of animals. Each change, however, means the discovery 
of an error, and brings us nearer to that stability in names which some 
day we- shall unquestionably reach. 
So much for the Robin’s generic designation. Passing now to its 
specific name, migratorius , which being again associated with a masculine 
generic name resumes its original termination of us, this name was 
applied to the bird throughout its entire North American range until 
1877, when Ridgway proposed the name propinquus for the Robin of 
western North America on the ground that in this race the outer tail- 
feather had little or no white, and on other characters, and this western 
bird, after sharing the various generic experiences of our eastern form, 
is now known as Planesticus migratorius propinquus (Ridgw.). 
After the recognition of a western race of the Robin under a trino- 
mial name, it would be obviously inconsistent to apply a binomial to 
