No. 3.] POSITION OF CHAMAZA. 487 
This change begins to be apparent in the Chickadees, as in 
Parus gambelt, or in the skull of P. carolinensis of a specimen 
kindly presented me by Mr. Coale, or in P. rufescens. It con- 
sists mainly in a decrease in the size of the openings of the 
nostrils, and a broadening of the culmenar bridge between 
them. And it is in such species as Parus tnornatus (of the 
subgenus Lophophanes) that we find a vastly different state of 
affairs prevailing (Fig. 5), for in them the upper bony beak is 
shorter ; less pointed anteriorly ; broadly rounded from side to 
side for the entire length of the culmen; the narial apertures 
subcircular instead of subelliptical in outline; their superior 
arcs widely separated by the great width of the nasal processes 
of the premaxillary. Viewing the skull upon its superior aspect, 
we find that in Chamea the frontal region is extremely narrow 
between the upper edges of the orbits, more so, in comparison 
with its size, than in any other species we have under consider- 
ation, although the feature is common to them all. The cranial 
vault, the sides and back of the brain-case included, is a smooth 
and rounded dome in Chamea, the Wrens, Tits, Accentor, Regu- 
fus, and the rest, though it differs in the various genera and 
species, both in form and relative extent. For the size of the 
bird, Chamea has decidedly the largest cranial capacity, Psaltri- 
parus about equalling it in proportion to its size, followed by 
Parus tnornatus, then Regulus and the Chickadees; while the 
Wrens have a small brain-case as compared with their size, the 
same applying to Accentor and our Warblers. Lophophanes has 
the posterior moiety of either orbital rim raised all round, a 
feature less marked in the Chickadees, while in Chamcea, the 
Bush-Tits, and Wrens it does not exist. 
Some good distinguishing characters are also to be found on 
a lateral aspect of the skull, more especially in the condition of 
the interorbital septum. Barely any bone is to be found here 
at all in Chamea, it being absorbed by a large vacuity occupy- 
ing the central part of the partition, separated only by a slender 
bar from the great coalesced openings above where issue the 
first pair of nerves. The optic foramina have also merged, and 
it consists now in a small, central, circular foramen completely 
surrounded by bone, at the median point of the upper arc of 
which the posterior end of the extremely delicate osseous rod 
which bounds the interorbital vacuity above is attached. Psal- 
