OF GALLINACEOUS BIRDS AND TINAMOUS. 209 
shown by the artist (Pl. XL. fig. 1). The basitemporal region of the Tinamou reminds 
me of that of the Rails. In front of the basitemporals, at the mid line, the basisphenoid 
is ridged ; this ridge passes along the rostrum, making it subcultrate: near the end of 
this elevation there is a small vascular foramen—the only remnant of the pituitary 
space (fig. 1). In typical birds this space is more or less scooped below, and is to some 
extent often wholly floored by the confluent angles of the basitemporals. This thick 
pituitary floor, and this subsidiary condition of the basitemporals, is thoroughly stru- 
thious); and there are Mammals, e.g. the Echidna and the Mole, in which these ele- 
ments (in them called the ‘‘lingule sphenoidales’’) bear as great a proportion to the 
basisphenoid as in the Ostriches. In the Emu, Rhea (Pl. XLII. fig. 1, bs.), and Ostrich 
the basisphenoid shows its junction with the basioccipital on the lower face of the skull ; 
if hidden at all] at the mid line in the Tinamou, it is only very slightly ; whilst in all 
birds above the ‘‘ Struthionidz’”’ this is impossible, on account of the secondary floor 
formed by the basitemporals. A few Mammals, e. g. Myrmecophaga jubata, have retained 
this secondary skull-floor; but I am not able to say to what degree the lingule have 
contributed to its formation’. 
The great posterior pterygoid processes of the basisphenoid are as well developed as 
in the Ostriches and birds generally ; they are quite rudimentary, although pretty con- 
stant, in Mammals, and often have the ‘ lingule”’ anchylosed to them. They culmi- 
nate in that most overgrown and extraordinary of all bony centres, the basisphenoid of 
the bird—a bone the counterpart of which in the Reptilia, e. g. Centropyx, Mocoa, 
Monitor, Anolis, Anguis, &c., is such a delicate splint, altogether in front of the massive 
basitemporals ; in the typical Ophidians, however, it is large. 
I mention these things, not for the sake of tediousness, and not by mistake, as wan- 
dering away from the subject of the affinities of the Tinamou, but simply because this 
bird has been placed by nature in the great highway of the vertebrate kingdoms, and 
not in the highway merely, but as it were on the very verge of the ‘‘ debateable land” 
where a mixed language is spoken, and where the burning life of the Mammal has 
lowered down and verges on the half-frozen life of the Reptile. Stretching far away to 
the right and left of these hot and cold regions of air-breathing vertebrate life is that 
goodly land, the land of the feathered tribes, where nature sports her virgin fancies, and 
where neither the Wren, the Nightingale, nor the Turtle want their mate. The Tinamou 
belongs to the most plebeian tribe of this lovely people, and it has in it also ashare of the 
nature of both those above and those below the class to which it belongs. As in the 
Rhea (Pl. XLII. fig. 1, 7.bs.), the “rostrum” of the Tinamou (PI. XL. fig. 1) is ex- 
tremely large and long—twice the relative length that it attains in the Fowl and in many 
aérial birds, and a third longer than in the Rails and Plovers (Pl. XXXVII. fig. 1, bs.). 
1 In the scarcely half-grown Hedgehog (Erinaceus) the “ lingule” are distinct: they are very small, and 
the large descending plates that form the inner wall of the drum-cavities are exogenous: they are the “ posterior 
pterygoid processes.” 
Denne 
