Observations on the Cubital Coverts of the Euornithes. 175 
better to retain them as they are than to introduce unneces- 
sary confusion by employing new names. In all birds soever, 
the remiges overlap distally, or in such a manner that the 
distal edge of each feather overlaps the proximal edge of the 
feather next distant from the vertebral axis, as they are 
viewed on the outer face of the wing. 
Turning now to the Cubital Majors, which are present in 
all the Euornithes, we find a remarkable feature, which was 
first made known many years ago by M. Gerbe. Whether 
the 5th cr. is present or is absent, its corresponding major 
covert is present invariably in all birds. Further, I have 
pointed out on more than one previous occasion, that in those 
wings in which the 5th cr. is present the Majors form an 
uninterrupted series, shortening, or lengthening, gradually, 
from one end of the cubitus to the other. But where the 
5th c.r. is absent an interruption of this uniformity becomes 
evident. The major coverts lengthen rapidly from the first 
to the fifth, which now becomes the longest of the Cubital 
Majors; while the sixth Major is often very considerably 
shortened, so as to appear to be not more than half the 
length of the exposed part of the feather preceding it. 
Moreover, when traced to its insertion, the seat of the feather 
is often at a higher level than that of the feathers on either 
side. The fifth Major is the longest, and the sixth one of the 
shortest, in all aquincubital birds, and the difference in length 
is so marked that it can easily be detected in the living bird, 
which thus bears on its wing a perfectly clear and certain 
indication of its aquincubitalism. In all birds of every 
known family, the Majors overlap distally, like the remiges. 
The overlap of the Medians, on the other hand, varies much 
from group to group, although it is, at the same time, constant 
for all birds presenting similar structural characteristics. To 
such an extent is this the case, that a mere glance at the 
arrangement, or style of imbrication, in the Medians, even in 
the case of a living bird, will suffice to show to what section 
of the Euornithes it belongs; and will even enable one, in 
the case of a bird whose anatomy is imperfectly known, to 
predicate with tolerable certainty what will prove to be the 
1 A convenient abbreviation for ‘‘ Fifth Cubital Remex,” 
