NO. 2.) APHRIZA VIRGATA. 323 
exceptions. For instance, we may say in a certain species, it 
has been found as a general rule that free ribs occur upon the 
13th and 14th vertebree, and that upon the 15th, the ribs connect 
with the sternum by costal ribs, but examples have been found 
in the same species where free ribs were found upon the 12th, 
13th, and 14th vertebrz; or again, a specimen of the same 
species showed free ribs on the 12th and 13th vertebre, while 
the ribs on the 14th connected with the sternum. This is by 
no means a fanciful description, as I have studied cases quite 
like it, and it only goes to show the utter hopelessness of laying 
down hard and fast lines in describing the cervical and dorsal 
divisions of the vertebral column in existing birds. On the 
other hand, I am inclined to believe that if the zotal number of 
vertebrze be counted in the skeleton of the chick of any par- 
ticular species, the number will be found to be quite constant. 
Now I believe, after carefully re-counting the vertebrz in the 
skeleton of the tail in the Mountain Plover (4. montanus), 
there should be a quzre placed after the number I have given 
in my memoir upon the osteology of that species, as I believe 
it should be seven, zo¢ counting the pygostyle ; further, I am 
inclined to think I made another miscount, for some reason, in 
my specimen of He@matopus, and too many vertebra have been 
mentioned as forming the skeleton of its tail in another paper 
of mine.” 
At the present writing I have not at hand the immature skel- 
etons of any of the species we have here under consideration, 
and consequently am unable to carry out the suggestions made 
in the foregoing paragraphs, so I can candidly admit that the 
number of vertebree given below as found in the sacra of the 
birds there enumerated must be taken cum grano salts ; although 
I will add that I counted them to the best of my ability: the 
process can often be assisted by holding the pelvis up to a strong 
light, with the dorsal aspect towards you. 
In my female specimen of A. vixgata, the ‘“ epipleural appen- 
dages”’ are present upon the pair of free ribs on the 15th 
vertebra, the reverse being the case in the skeleton of two males 
1 [bid., p. 97. 
2 Shufeldt, R. W., “Osteology of Mumenius longirostris, with notes upon the 
Skeletons of other American Limicole.” Fourn. of Anat. and Phys. London. Vol. 
XIX., October, 1884, pp. 71, 72. 
