96 SHUFELDT. [Vot. III. 
(Scturus); and yet, while there is much to base such an opinion 
upon, the fact still remains that the typical passerine skeleton of 
Cinclus mexicanus is powerfully impressed with strong turdine 
characters. 
My knowledge of the osteology of our American Family Mo- 
tacillide rests upon my having carefully studied the skeletons 
of a number of species of the genus Axzhus, and such material 
is before me at the present writing. 
The sku// in such a form as Anthus pensilvanicus 1s an exceed- 
ingly delicate structure in all its parts (Fig. 13), the interorbital 
septum being markedly deficient in bone; the pterygoids and 
the zygomz wonderfully slender rods; while the palatines and 
premaxillary are about as frail as we ever see them in the Class. 
Taken as a whole, the skull of this Pipit is almost identically 
like the skull of Sczurus motacilla, while in the rest of its skel- 
eton, more particularly in the sternum and pelvis, we see some 
rather strong traces of the Thrush: especially is this true of the 
last-named bone; not in any ways enough, however, to detract 
from the fact that the J/o¢aci/lide see their nearest affinity in 
the genus Sczurus of the Minotcltzd@, and the relationship here 
is very close. 
This last-mentioned family is the next one we have in order 
to consider, and in our American avifauna it is made to contain 
the Wood-Warblers, a lovely group of birds, that in their struc- 
ture seem to have a tincture of every morphological variation to 
be found in the entire passerine order. On p. 287 of the second 
edition of his Key, Coues says of them that “the warblers 
grade so perfectly towards the tanagers that they have all been 
made a sub-family Zanagride (where possibly they belong). 
The affinity of some of them with Cwredzda, or honey creepers 
of the tropics, is so close that the dividing line has not been 
drawn.” We well know how J/cterta branches off in another 
direction, while the Redstarts are strongly inclined towards the 
Tyrannide. True as all this undoubtedly is, we can neverthe- 
less, through a critical examination of a series of skeletons of 
the genera making up the Family in this country, throw a little 
light into so closely affined a group, and perhaps reveal some 
of the veins of the mystery. To do this we should choose a 
type-centre as it were, and this can be very well represented by 
the genus Dendroica, the species of which probably presents in 
