1905. | OSTEOLOGY OF THE EURYLAMID&. D3 
Though I looked carefully for this slip, I failed to find it, yet I 
examined three or four specimens. 
Forbes showed that, in the matter of the syrinx, the Hurylemide 
agree most nearly with the Philepittide of the Old World; and, 
after that, with the Cotingide, Pipridee, and Tyrannide of the New 
World. This organ is of the ‘ Mesomyodian,” “ tracheo-bronchial ” 
type, or, to adopt Gadow’s term, the syrinx is tracheo-bronchial 
and ‘“* Anisomyodean.” 
Had the syrinx instead of the plantar tendons been adopted as 
the basis of classification for this group, then the Cotingide 
would have been regarded as the more primitive group, inasmuch 
as in Lipaugus cineraceus the intrinsic muscle, according to 
Beddard, is of great width, “which seems to foreshadow its 
division in the Oscines into a complex of muscles... .” 
The many characters which the Eurylemide and Cotingide 
share in common—skeletal, muscular, syringeal, pterylological, 
&e.—are surely proofs that these two groups are much more nearly 
allied than is generally supposed to-day: the lkenesses are too 
many and distinct to be put down to convergence or correlated 
variation. 
The fact that the spina externa of the sternum is simple is 
generally bracketed together with the plantar tendons, and other 
characters, so as to emphasise the primitive character of the 
Eurylemide. But this same peculiarity of the sternum occurs 
again in the Cotingide. The pterylosis of the Eurylemide is 
generally regarded as peculiar : as a matter of fact, it is hard to 
distinguish from that of the Cotingide. The syndactyle foot 
again turns up—in the Cotingide. We have already described 
the close resemblances which obtain in the skulls of these two 
groups. 
Turning now to the muscular system. The syringeal muscles 
we have already referred to. They offer no striking peculiarities 
of structure. Indeed, the only muscles which seem to call for 
comment in this summary are the brevis and longus divisions of 
the deltoidews. The separation of this muscle into two distinct 
parts is nowhere so complete as in the Passeres. 
In its primitive (archicentric) condition, this muscle arises, in 
part from the acromion and inner face of the expanded free 
end of the clavicle and in part from the os humero-scapulare and 
crista lateralis of the humerus. It is inserted by a common 
tendon into the base of the ectepicondyloid process; the tendon 
forming the terminal of a practically homogeneous muscle. 
I have not yet had time to study the apocentricities of this 
muscle, but it would appear that as specialisation proceeds it 
breaks up into two more or less equal and perfectly distinct 
muscles terminating in a common tendon: later the brevis 
portion becomes suppressed and the longus much shortened, each 
receding farther and farther up the shaft of the humerus. 
T have only just realised the potentialities of this muscle as a 
factor in systematic work, and therefore have no large series of 
