538 Letters, Extracts, and Notes. 



of Zoological Nomenclature, which was finally adopted by 

 the Berlin Congress of 1901^ and published in English^ 

 French, and German at Paris by F. R. De Eudeval. 



There are many difficult questions in nomenclature which 

 cannot be dealt with under the rules as contained in the 

 code, or in which the interpretation of the code is doubtful. 



The Commission undertakes to investigate such of these 

 questions as are submitted to them by various zoologists, 

 and to give an "opinion" as to the best course to be adopted; 

 but it must be understood that such " opinions " are not 

 necessarily final decisions until they have been verified as 

 amendments to the Code of Rules of Nomenclature and 

 approved of by the Zoological Congress at one of its 

 meetings. 



Under the title of " Opinions rendered by the Inter- 

 national Commission on Zoological Nomenclature/^ the 

 Smithsonian Institution at Washington has undertaken to 

 publish the findings of the Commission on these difficult 

 questions. The first batch, " Opinions 1-25," was issued in 

 1910, and we have recently received the last one, " Opinions 

 57-65." 



As it may not be easy for members of the Union to obtain 

 the "Opinions/' and as they deal with many questions which 

 do not directly concern ornithologists, we have thought it 

 may be useful to give shortly the " Opinions " which are 

 of special interest in our own department : — 



Opinion 16 deals with the fixing of the type of certain 

 genera of Linnseus, and it agreed that where Linnseus cited 

 in his synonymy, under one of the species in the genus, 

 the generic name as used by pre-Linnean writers, that species 

 is the type of the genus. 



For instance, the genus Alca was instituted by Linnseus 

 for the Auks, and contained six species: ^orc?a = Razorbill, 

 impennis = (jrea.t Auk, arc^ica = Puffin, lomvia = G\xi\\evaot, 

 £/ryUe = B\ack Guillemot, and a//e = Little Auk. In the case 

 of " tor da" the only reference given is ''Alca'' ; the Razor- 

 bill was so called by all the older authors from Clusius to 

 Albin. We may therefore consider that " tarda " is the 



