178 MR. W. K. PARKER ON THE OSTEOLOGY 
pterygoid process of the basisphenoid. The ‘‘ Struthionide,”’ as we shall see, offer the 
very opposite of this condition, this anterior pterygoid process being in them placed so far 
backwards as to receive only the end of the pterygoid, which is jammed in between that 
long peduncle and the os quadratum (Pl. XLII. fig. 1, pg.). We shall soon see how this 
bears upon the affinities of the Syrrhaptes and the Tinamou. - 
The large, inflated, shell-like posterior pterygoid processes of the Hemipodius (Pls. 
XXXIV. & XXXV.) are more like those of Vanellus even than of Columba ; least of all 
are they like the same parts in the Quail. So wide a ‘‘ trumpet” do they form, with 
the help of the basitemporals and anterior tympanics below, that the Eustachian tubes 
are direct continuations of the cavity of the ear-drum. Their anterior termination, 
however, is very small, as they contract somewhat rapidly, and then open into one 
common vestibule, above the lip of the coalesced basitemporals, and beneath the 
scooped proximal portion of the rostrum of the basisphenoid (Pls. XXXIV. & XXXV. 
fig. 1). 
The rostrum of the Hemipodius (b.s.) is short, thick, and cellular; anteriorly it is 
sheathed by the broad, short vomer; then three-fifths more of it is embraced by the 
ascending plates of the palatines and pterygoids. It is then free for some distance 
—two-fifths, or nearly, of the posterior part. No trace is left of its suture with the 
base of the ethmoid. ‘The presphenoid is high up out of the way of the basisphenoid 
(p.s. & b.s.). The ‘‘ sella turcica” is very neat and very deep; and the carotid fora- 
mina, at its narrow, backwardly placed fundus, large. The anterior clinoid processes 
are wide apart and sharp: the posterior pair have coalesced (as is usual), and form a 
thick, forwardly inclining wall, against which the base of the brain leans. ‘T'wo bosses, 
near together, show, in the adult, that the posterior clinoids were ossified from each 
side, and that they thickened before they met. The alisphenoids of the Hemipodius 
(a.s.) are well ossified: they, with the imperfect orbital plates of the frontals and the 
exogenous orbital ale of the presphenoid, wall-in the brain antero-inferiorly. There 
are two distinct eminences for muscular attachment on each alisphenoid; these 
represent the external pterygoid plate of Mammals. The ale of the presphenoidal 
ossification have coalesced with the frontals and alisphenoids at their point of junction. 
A small, flat, narrow process descends from the presphenoid towards the junction-line 
of the high part of the base of the rostrum with the postero-inferior portion of the 
ethmoid. The presphenoid, however, interdigitates by sharp sutural teeth with the 
postero-superior process of the ethmoid (p.e.). This latter process is longer than the 
one that runs forwards to meet it. Not half the interorbital septum is ossified ; for, 
although the ethmoid fills up some space below, it is cut away in a concave manner 
between its two backward processes—a large, oval, membranous space having been 
left by the feeble growth of what was, in an early state of the embryo, a perfect 
cartilaginous septum. 
Between the postero-superior process of the ethmoid of Hemipodius, and the anterior 
