ORNITHOLOGICAL CLUB. 61 



distinction fails to hold. In the Vireonidce, for instance, species of 

 the same gemis have indifferently " nine " or " ten " primaries. 

 Thus, Vireo philadelphicus and V. gilvus are two species so much 

 alike that presence or absence of a spurious "first" primary be- 

 comes the readiest means of distinguishing them. Noting this 

 remarkable circumstance in 1865, Professor Baird was led to look 

 more closely into the matter. His results are summed on page 325 

 of the "Review of American Birds" (see also p. 160); from which 

 it appears that in those Vireos which seem to have only nine prima- 

 ries, two little feathers, distinct in size, shape, and to some extent in 

 position from the general series of primary coverts, are found at the 

 base of the supposed first primary ; while in those Vireos with an ob- 

 vious spurious first primary, making ten in all, only one such feather 

 is found. " In all the families of Passeres where the existence of 

 nine primaries is supposed to be characteristic," he continues, " I 

 have invariably found, as far as my examinations have extended, 

 that there were two of the small feathers referred to, while in those 

 of ten primaries but one could be detected." He does not specify 

 how far his examinations extended. 



Believing this to be an important matter, which would bear fur- 

 ther investigation, I have been led to look into the question, with 

 the most satisfactory results, confirming Professor Baird' s observa- 

 tions, and extending them to include every one of the North Ameri- 

 can families of Oscines, excepting, perhaps, Laniidce (in Collurio) and 

 Ampelidce (in Ampelis). With the possible exception of the two 

 genera specified, I find, on examining numerous genera of all the 

 North American families, that those rated as 10-primaried have but 

 one of these little feathers, while all the rest have two. 



The Alaudidce, like the Vireonidce, show a variability of the 

 primaries. In our genus Eremophila, in which only nine primaries 

 are developed, there are two of the small feathers above mentioned. 

 The overlying one is exactly like one of the primary coverts ; the 

 other, though not very dissimilar, more resembles an abortive 

 primary. In Alauda arvensis, where there is a minute but obvious 

 spurious quill, there is but one such feather. In Galerita cristata, 

 with a spurious quill about two thirds of an inch long, there is like- 

 wise but one. 



In clamatorial Passeres, perhaps without exception, there are ten 

 fully developed primaries, the first of which may equal or exceed the 

 next in length. In the single North American clamatorial family 



