Count T. Salvadori on Tauysiptera dea. 551 



interpret facts, and if we do this we shall often find that an 

 excellent geographical form, evident at a glance when con- 

 fronting two series, contains single individuals which do not 

 follow the rule, but are intermediate or do not represent the 

 various characters by which the two forms can generally be 

 distinguished. Therefore, though I certainly require that 

 two species should be distinguishable, I do not require that 

 each individual of every geographical form (" subspecies") 

 should at once be distinguished. If thirty specimens of a 

 British bird are distinguishable from thirty from the Con- 

 tinent of Europe and one is not, then I must recognise the 

 two forms as subspecies. The one which does not follow 

 the rule may be intermediate or aberrant, though generally 

 it may only be a straggler from the other country, but it 

 cannot give us the right to overlook the fact that there are 

 two different forms. — Sine ira ! 



XLI. — Note on Tanysiptera dea. 

 By Count T. Salvadori, F.M.Z.S. 



Mr. Otto Kleinschmidt, in a very curious paper on the 

 " Ornis von Marburg an der Lahn " (Journ. f. Orn. 1903, 

 pp. 440-507) has already shewn (p. 461) a strong case of the 

 inconvenience of going back in nomenclature to the tenth 

 edition of Linne's ' Systema Naturae ' (1758). In the edition 

 of 1758 the description of Tardus iliacus (p. 1G8) is that 

 which fits T. musicus (alls subtus flavescentibus . . . linea nulla 

 super ciliorum alba), while the description of Tardus musicus 

 (p. 169) is evidently the one which fits T. iliacus (alis subtus 

 ferrugineis, linea super ciliorum albicante). Linne, in the 

 twelfth edition of the ' Systema Naturse/ corrected the mis- 

 take that he had made in the tenth edition, and T. iliacus 

 is there described as follows : — " alls subtus ferrugineis, 

 superciliis albicantibus " ; while the description of T. musicus 

 runs as follows : — " remigibus basi interiore ferrugineis/ 3 



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