Page 120. 
218 ON CERTAIN MUSOLES OF BIRDS. 
Professor Huxley’s term Schizognathous, and the nasal characters 
expressed by my term Schizorhinal, are homalogonatous. All non- 
struthious birds with a truncated vomer are anomalogonatous. 
As to what appear to me to be the main divisions of the homalo- 
gonatous birds, the myology of the thigh does not give more than a 
certain amount of assistance. In list I. it will be seen that large 
brackets precede the names of the smaller divisions or families, sepa- 
rating them into what to me are worthy of the dignity of orders. 
From these it is evident that I would divide homalogonatous birds 
into four orders, I. Galliformes, II. Anseriformes, III. Ciconiiformes, 
and IV. Charadriiformes (Schizorhine). These must be considered 
separately. 
The Galliformes include all the birds in which there is any 
approach in structure to the common Fowl. With the exception of 
the Psittaci (which in other points also are peculiar), and the Oucu- 
line from amongst the Cuculide, they all possess the accessory 
femoro-caudal (B) well developed. The semitendinosus (X) and 
the accessory semitendinosus (Y) are always present, and, except in 
Casuarius, Dromeus, and some Psittaci, the ambiens is to be found 
well developed. 
The presence of both the accessory femoro-caudal and the accessory 
semitendinosus (that is, of both B and Y in their myological formula) 
is the most characteristic feature which they have in common, giving 
the formula B. X Y as typical. 
The Anseriformes include most of the web-footed birds. Their 
most marked characteristic is the presence of the accessory femoro- 
caudal (except in Bulweria), whilst the accessory semitendinosus is 
absent, except in the Storm-petrels. With the exception of the 
Podicipide, the femoro-caudal is present ; so that their formula is nearly 
always A B. X. Excluding Podiceps and a Storm-petrel in the case of 
one species examined, I have always found the ambiens present. 
The Ciconiiformes are less easily defined than the other groups. 
The ceca coli are never long; the accessory femoro-caudal is never 
present; and the obturator externus is frequently more developed than 
in other birds, to replace it in action. It is in the pectoral region that 
these birds most closely agree. The strong short anterior costo-cora- 
coid ligament, the bowed space between the superior margin of the 
second pectoral muscle and the fureula, and the frequently complicated 
arrangement of the great pectoral, whereby it is developed in a super- 
ficial and a deep layer (in which, by the way, the Procellariide agree 
with them), all point to a not far distant relationship. The Ardeide 
are the most aberrant of the order, the ambiens muscle being always 
absent in them at the same time that there is only one colic cecum. 
The Charadriiformes correspond to the Schizorhine, so named by 
