TOPOGRAPHY OF THE HEAD. 19 
§ 41. Heap. Though smaller than either of the parts already considered, 
the head has been more minutely mapped out, and such detail is necessary 
from the number of recognizable parts or regions it includes. Without pro- 
fessing to give all that have been named, I describe what will be needed for 
our present purposes. 
(a). “Top of the head” is a collective expression for all the superior sur- 
face, from base of the bill to nucha, and on the sides nearly or quite to the 
level of the upper border of the eyes. This is pilewm (fig. 4,1, 4,6) 3 it 
is divided into three portions. orehead, or frontal region, or, simply, “the 
front” (Li. frons; fig. 4,1) includes all that slopes upward from the bill — 
generally to about opposite the anterior border of the eyes. Middle head or 
crown (lL. corona), or vertex (L. vertex; fig. 4,4), includes the top of the 
head proper, extending from forehead to the downward slope towards nucha. 
This last slope is hind head, or occiput (fig. 4,6). The lateral border of all 
three together constitutes the “superciliary line,” that is, line over the eye 
(Lat. super, over, cilia, hairs [of the brows in particular]). 
(b). “Side of the head” is a general term defining itself. It presents for 
consideration the following regions: orbital, or circumorbital (L. orbis, an 
orb, properly, here, the circular hole in the skull itself that contains the eye- 
ball; fig. 4,3) is the small space forming a ring around the eyes; it em- 
braces these organs, with the upper and under /ids (Li. palpebre) ; where 
these meet in front and behind respectively, is the anterior canthus and poste- 
rior canthus. The region is also subdivided into supra-orbital, infra-orbital, 
ante-orbital and post-orbital, according as its upper, under, front or back por- 
tion is specially meant. The position of the circumorbital varies in differ- 
ent families; generally, it is midway, as stated, but may be higher or lower, 
crowded forward toward the base of the bill, or removed to the back upper 
corner of the side of the head, as strikingly shown in the woodcock. The 
aural or auricular (fig. 4, 3) region is the part lying over the external ear- 
opening; its position varies in heads of different shape; but in the vast 
majority of cases it is situated a little behind and below the eye. Wherever 
located it may be known at a glance, by the texture of the auricular feathers 
(shortly, the auriculars) covering the opening. Doubtless to offer least ob- 
stacle to passage of sound, these are a tuft of feathers with loose vexilla 
(§ 3) from greater or less disconnection of the barbs (§ 3); and they may 
collectively be raised and turned forward, exposing the ear-opening ; they are 
extremely large and conspicuous in most owls. “Temporal region,” or the 
temples (Li. ¢empora, times, or age, because an elderly man’s hair whitens 
there first) is a term not often used ; it designates the part between eyes and 
ears, not well distinguished from the post-orbital space. At the lowermost 
posterior corner of the head a protuberance is seen, or may be felt; it is 
where the lower jaw is hinged to the skull, and is called the “angle of the 
jaw ;” it is generally just below and behind the ear. The lore (L. lorum, 
strap or thong; hence, reins or bridle ; hence, place where the main strap of 
a bridle passes; fig. 4, 2) is an important region. It is generally pretty 
