546 ON THE ANATOMY OF ZCHMOPHORUS MAJOR.  ([Apr. 21, 
and to the Plovers being only seen in one species of each group and 
in the aberrant Rhynchops. There is, moreover, the same amount of 
hikenessto the Limicole proper in a small point which may be regarded 
as of equal importance. The bicepsslip, always present in the Alcide, 
has, at least as a rule, rather unusual relations. Thus in Alcea 
torda Fiirbringer figures it as attached partly to the patagial 
membrane and partly to the inner of the two brevis tendons. In 
the Gull the insertion is the more normal one, 7.¢. on to the longus 
tendon. In Fratercula arctica the muscle is inserted upon the 
middle of the three brevis tendons. Now in a specimen of Tringa 
canutus (doubtless individual variation), I found a second biceps 
slip in addition to the usual one, which was inserted on to the outer 
of the two brevis tendons. This tendon I take, for reasons already 
explained, to correspond to the middle of the three tendons of 
Fratercula. 
I have carefully studied the windpipe of a number of Auks, and 
can find no reasons for associating them especially with the Gulls 
from an examination of this organ. The syrinx is seen in its most 
characteristic, even exaggerated, form in Ceratorhina monocerata. 
In this Auk (fig. 6) the first bronchial semiring is the shape 
of half an ellipse—a gross exaggeration of the generally arched 
form of this ring in the avian syrinx; the same form is shown by 
the second bronchial semiring, which lies as it were inside the first 
Fig. 6. 
Fig. 6.—Syrinx of Ceratorhina monocerata : 7, intrinsic muscles. 
Fig. 7.—Syrinx of Lomvia troile: i, intrinsic muscles. 
and is concentric with it. The intrinsic muscles are attached to 
the first. Nothing of this kind occurs in any Gull or Limicoline 
bird known to me. In other Auks, however (fig. 7), the syrinx 
is decidedly more typical in form. It is an interesting fact 
that we can arrange the family into two subfamilies according to 
