1915 J General Notes. 23o 



i-epresenting several specific types. These fall into two groups, the larger 

 of which, including the Gold-crests and Fire-crests is Holarctic in distribu- 

 tion, the other containing the Ruby-crowned Kinglets only (a continental 

 species of three races and a closely allied island species) being strictly 

 Nearctic. 



As long ago as 1850 Cabanis referred Regulus calendula to his genus 

 Phyllobasileus, which included small Willow-Wren-like forms now included 

 in Reguloides. Three years later, however, concluding that calendula 

 was more nearly related to true Regulus yet generically distinct he proposed 

 for it the name of Corthylio. 



As is well known the type of Regulus (R. regulus) and its immediate 

 allies differ from R. calendula (and from all other birds as well) in the 

 presence of a single flat feather overlying each nostril. This represents the 

 several much smaller and more bristly antrorse plumules of the Ruby-crown. 

 The latter is further distinguished by longer tarsi, a larger and wider bill, 

 absence of stripes on the head and uniform olive-green crown of the female. 



In spite of these differences, however, it has not seemed necessary to 

 separate the Ruby-crown from Regulus, and Cabanis's genus has been 

 almost universally ignored. The discovery of an additional character 

 now renders necessary, in my opinion, the recognition of Corthylio. 



While recently identifying some bird remains from the crop of a Sharp- 

 shinned Hawk, I was struck by the peculiar form of the hind-toe of a foot 

 which proved to be that of a Golden-crowned Kinglet. The pad forming 

 the sole of the toe for its basal half is approximately obovate (broader 

 terminally than basally), abruptly contracted distally, the sub-truncate 

 end strongly contrasting with the narrow terminal half of the toe. This 

 conspicuous pad is shorter than the rest of the toe beyond it (excluding 

 the claw) and reticulated into about a dozen polygonal sections. No other 

 birds examined (including Mniotiltidae, Sylviidse, Fringillidse, Parida? and 

 Vireonidse) at all closely approach the species of true Regulus in these 

 peculiar features, in which they seem to be as unique as in the supranasal 

 plumule. 



In the ordinary song-bird foot the sub-basal pad of the hallux is tapering 

 or gradually rounded terminally, where it is usually not very strongly 

 defined, longer than the distal portion of the toe, its superficial divisions 

 minute and very numerous. Reguloides superciliosus is normal in these 

 respects, and Regulus calendula exhibits but a slight approach to true 

 Regulus in the form of the pad, which is longer than the rest of the toe, 

 the reticulations being larger than usual but smaller than in true Regulus. 



If the validity of Corthylio as a genus is conceded the names of the Ruby- 

 crowned Kinglets will stand as below. The Guadalupe form is in my 

 opinion (based on examination of an excellent series) specifically distinct. 

 Neither in coloration (at least in fresh plumage), in the relation of bill and 

 tarsal length to that of the wing, nor in the mutual proportions of the 

 ninth and tenth primaries, is there any evidence of intergradation with the 

 continental forms. " Regulus cuvieri " is referable to true Regulus. 



