on the Topography of a Bird.



167



.. the belly.


.. the crown of the head.


.. bristles surrounding the gape.


.. yoke-footed: having two toes in front and two behind

(Parrots).



EXPLANATION OF PLATES.


Plate I.


Diagram illustrating the Topography of a Bird.


Plate II.


Fig. 1. Upper surface wing of a Little Stint ( Tringa

viinuta ) to show ( a ) the difference between distal and proximal

overlap (the former shown by the major, and the latter by the

median coverts), and ( b) the “faulting” which results in the

formation of the intercalary row in the majority of birds having

diastataxic wings.


Fig. 2. Upper surface of a portion of the wing of an

Owl, to show the diastataxic condition—the absence of a quill

between the fifth pair of major coverts. The quills or remiges

are heavily shaded in black.


Plate III.


Fig. 1. Head of an Accipitrine bird to show the “tooth”

on the tomium or cutting edge of the beak, and the “cere” or

soft skin at the base of the beak. The Rhamphothcca or beak

sheath is simple.


Fig. 2. Beak of an Albatross to show the compound con¬

dition of the Rhamphotheca or beak sheath, which is composed

of several distinct elements.


Fig 3. Foot of a bird to show the schizothecal podotheca

wherein the horny investment of the foot is made up of several

separate pieces.



Venter


Vertex


Vibrissae


Zygodactyle



