IIO SHUFELDT. [VoL. III. 
and the first quill of the wing spurious, are birds of relatively 
very small brains, and the young males in Regulus calendula, at 
least, do not take on the plumage of maturity until the second 
year. Good, strong, sub-family lines must be recognized as 
being drawn between the Reguline and the Polioptilina. 
From the last three-mentioned families in my serial arrange- 
ment, we pass naturally to such groups as the Motacillide 
and Vireonide,; the former being hardly anything more than 
terrestrial Sylvias, and the latter, judging from their skeletons, 
have closer affinities with the Warblers than with any other 
family which we have thus far investigated. After these the 
true Creepers (Certhizde) have been placed, forms which, oste- 
ologically and otherwise, have no especial claim to be ranked 
with birds of undoubtedly higher organization. This remark 
applies with equal force to the Alaudide,; indeed, still more 
pointedly to them, for the Larks in addition have an anomalous 
structure of the tarsal theca, and one from its double scutella- 
tion of perhaps a lower type organization. In them, too, the 
young have a different plumage from the parents. 
For a long time I was at a loss to know where to place the 
Swallows ({/zrundinide), and they have been crowded to near 
the foot of the list, not that they have not a few points in their 
economy indicative of a certain degree of rather high specializa- 
tion ; still, although truly passerine birds, they are birds of com- 
paratively small brains, and their young differ in their plumages 
from the parents; and, while we do not yet know the exact 
affinities of the Wzrundinide, all the speculations in that quarter 
have been in the direction of associating them with groups of 
recognized low type of organization. 
Newton says of them: ‘ But altogether the family forms one 
of the most circumscribed, and therefore one of the most 
natural groups of Osczues, having no near allies; for, although in 
outward appearance and in some habits the Swallows bear a 
considerable resemblance to Swifts, the latter belong to a very 
different order, and are not passerine birds at all, as their struc- 
ture, both internal and external, proves. It has been sometimes 
stated that the Hzrundinide have their nearest relations in the 
Flycatchers; but the assertion is very questionable, and the 
supposition that they are allied to the Ampelide, though possibly 
better founded, has not as yet been confirmed by any anatomical 
