6 Osteology of Porzana Carolina. 
it must be remembered that the fundamental principles 
upon which the skull is built for the species, using that 
word in its present biological acceptation, remain the same. 
Such principles I have attempted to seize upon for my 
descriptiqn of the skull of this Rail, as given above, explic- 
itly stating the exceptions when they have fallen within 
my observation. 
Viewed from above, the mandible has the true V-shape, 
as we might be led to suppose from Fig.2. The symphysis 
is short, being scooped out above, and rounded below. 
Kach ramal margin is cultrate along its superior margin, 
and smoothed off inferiorly. The sides included between 
them are, for the most part, flat, and nearly vertical. A 
large ramal vacuity is outlined, and would exist, but in 
all the specimens examined the splenial element usually 
succeeds in filling the most of it in. 
As in some of the water birds, we find a small foramen 
in the surangular piece that appears to be constant. I have 
yet to find a specimen in which the coranoid process is well 
developed ; indeed, its usual site in other birds is here 
smooth and unbroken. 
Coming to the articular cups at the hinder ends of the 
ramal limbs, they are found to be deep and drawn out into 
the usual processes towards the mesial plane. At the tip 
of each of these occurs a single pneumatic foramen. 
Huxley lays down the rule that the angle of the mandi- 
ble in the Geranomorphe is truncated, and, strictly speak- 
ing, this is the case in the Rail we have before us; there 
is, however, a strong recurved process springing from the 
postero-external angle of either of these mandibular cups 
for the quadrates (Fig. 1), that fully merits attention in this 
connection. 
All the elements of the hyotdean apparatus are very deli- 
cately constructed, the thyro-hyals curving up behind the 
cranium, are reduced to almost hair-like dimensions, so 
slender is their calibre. Glosso-hyal and cerato-hyals both 
remain in cartilage throughout life, and the basi-branchials 
seem always to be in one piece in the adult bird ; the first 
one being nearly double the length of the second. 
