Vol 'l*i9 XVI ] General Notes. 295 



erythropus, Hirundo fissipes, Fringilla erythrophthalma, Parus atricapillus, etc., 

 showing that he rightly considered these specific names to be adjectives. 

 From erythros and melas comes the adjective erythromelas, fem. erythro- 

 melaena, neut. erythromelan, red and black. Now if Piranga is considered 

 feminine, as it is (Piranga rubra), the Scarlet Tanager's name is Piranga 

 erythromelaena. There is no escape from this except for those who refuse 

 to make an adjectival specific name conform in gender to the generic 

 name with which it is associated. 1 — Walter Faxon, Lexington, Mass. 



Constant Difference in Relative Proportions of Parts as a Specific 

 Character. — In the oft-recurring discussions of what constitutes a species 

 and the difference between subspecies and species, one interesting kind of 

 intergradation which might be termed " pseudo-intergradation " had not 

 been mentioned. 



This is well illustrated by certain of the Guadalupe Island forms, not- 

 ably the Rock Wren iSalpinctes) which has at times been regarded as a 

 species and again as a subspecies even by the same authority. 



The Guadalupe bird, together with its near ally of San Martin Island, 

 differs from its relatives of other islands and the mainland in its longer 

 bill, relatively shorter wing and darker coloration. The difference in 

 proportions is constant so far as known; only exceptionally short-billed 

 specimens agree in the length of this member with the longest billed indi- 

 viduals of other foims, while only very long-winged examples fail to differ 

 from short-winged birds of the related races. This, however, has been 

 held to be intergradation and on these grounds the Guadalupe bird, S. 

 guadeloupensis, was degraded to subspecific rank by Ridgway in 1904, even 

 before the somewhat intermediate race S. g. proximus was discovered. 



Individuals agreeing in the length of the bill, however, naturally exhibit 

 the maximum difference in the length of the wing, while those agreeing in 

 the wing can be distinguished by the length of the bill. In other words 

 the ratio of bill to wing length in the two species S. obsoletus and S. guade- 

 loupensis is constantly different and furnishes a diagnostic character by 

 which the species may always be distinguished. In the former the wing is 

 more than three and a half times the length of the bill, in the latter less than 

 three and a half. In addition there is a well-marked difference in color. 



It seems reasonable to consider such differentiation in proportions when 

 developed to the point where there is constant difference in ratio as of 

 specific value. Measurements appear to indicate that this point has been 

 reached in the Rock Wrens, and that the dark, long-billed forms should 

 therefore be regarded as specifically distinct from the paler, shorter billed 

 races. The same conclusion was arrived at by Swarth in 1914 (Condor, 

 XVI, p. 216). 



1 It is interesting in this connection to note that Ridgway (Bird N. and Mid. Amer., 

 II, p. 101) rejects P. erylhromelcena Salv. 1868 because of P. erythromelas Vieill. 1819 

 but does not alter the latter I — Ed. 



