6 
Osteological Studies of the Subfamily Ardeince. 
if actual anchylosis does not take place, we can at least be well 
assured from the paragraph I have quoted above, that the clavicles 
do curve backwards to come in close relation with the sternum, a 
very different condition being present in th zArdemce, where their 
lower thirds curve gently forwards in the manner described 
above. 
Of the Pelvis and Coccygeal Vertebra :—A year or so ago I 
made a number of anatomical drawings for Professor Coues, these 
now illustrate his admirable ‘ ‘ Key to North American Birds, ’ ’ 2d 
Edition. Among these drawings I figured the under view of the 
pelvis of A. herodias , the bone now to be described. It is figure 
60, in the work alluded to, and as the present paper contains two 
other views of this pelvis (Figs. 13 and 14), I have intentionally 
drawn them from the same specimen, which I was so fortunate as 
to still have by me. 
The twenty-fourth vertebra of the spinal column of this 
heron is the anterior one of the series that becomes incorporated 
by complete anchylosis with those other neighboring bones which 
go to form the pelvis Indeed, so far as I have been able to ex¬ 
amine, it is this vertebra throughout the Ardeince that holds this 
place ; it is marked dl in my figure in Dr. Coues’ “ Key.” 
This twenty fourth vertebra possesses a pair of free ribs which 
have already been described above ; its neural spine is continuous 
with the common median crest of the others behind ; and its 
broad diapophyses meet the under side of the ilia, on either side, 
to anchylose with them. As in the remainder of the pelvic series 
of vertebrae, this bone is highly pneumatic, the foramina entering 
the bones much in the same manner as we found them doiim in 
O 
the dorsal region. 
The next four vertebrae behind the twenty-fourth, or the 
twenty-fifth, sixth, seventh and eighth, throw up apophysial 
abutments against the iliac w r alls, to complete!} 7 fuse with them. 
After w T e pass the twenty-eighth we suddenly meet the pelvic 
basin proper which is here deep and ample ; the apophyses of the 
three next succeeding vertebrae, or the twenty-ninth, thirtieth, 
and thirty-first are thrown so directly upwards against the pelvic 
bones, that they cannot be seen on direct ventral aspect. This is 
the region of the greatest enlargement of the neural canal, and 
also the bones through which it passes are here more massive in 
order to contain that part of the cord from which the sacral plexus 
