Shufeldt on the Osteology of Cinclus Afexicanus. 2 IC) 
particularly to those whose aim it is to pursue the study more than 
“skin deep.” 
In the adult Dipper the pelvic limb, as far as its skeleton is 
concerned, is made up of the most usual number of bones; the 
thigh having the femur , the leg the tibia and fbula , a patella , 
the tarsus the bone tarso-metatarsus , and finally a foot arranged 
upon the plan of four toes, with first, second, third, and fourth 
digit composed of 2, 3, 4, and 5 joints respectively. 
I have already said that these bones are non-pneumatic, they 
are also of lengths proportionate to the size of the bird, the 
claws being curved about as much as they are in a typical Thrush. 
Anatomists have described certain general points for examina- 
tion on these long bones composing the leg ; many of these are 
present, but we shall only call the student’s attention to a few of 
them, so as to make clear what we have to point out hereafter. 
Nothing of striking variance marks the femur, as distinguishing 
it from the common form of the bone among birds of this class. 
The same might be said of the tibia, but we must note the two 
large flaring processes at the anterior and upper end of this, the 
larger bone of the leg ; in this bone, too, the condyles are well 
developed below. The tarso-metatarsus, or the bone of the tar- 
sus, we observe in the old bird, has rather a slender shaft, pre- 
senting for examination at its upper end the usual dilatation, 
crowned by a smooth, undulating surface to articulate with the 
tibia ; behind this, at the same end, we find a tuberous process 
that has given comparative anatomists no little trouble to name ; 
but we will speak of this further on. The lower end of the tar- 
so-metatarsus has the little lateral facet for the diminutive first 
tarsal bone, and the three trochleas for the other toes. 
Let us now, after this brief survey of the bones in the adult 
take up the young of this species. We find first that the femur 
has grown in the usual manner, its lower end bearing the two 
large condyles has been formed by one epiphysis which included 
both of these articulate surfaces. Nothing of particular interest 
is to be obser\ed in the development of the fibula or the small 
“splint bone” of the leg. The superior end of the tibia has 
been formed by the epiphysis including the two large processes 
that I spoke of above. These plates are called the procnemial 
and the ectocnemial processes, the inner and outer one respect- 
ively. They are turned slightly outwards, springing abruptly 
