THE SKULL IN THE WOODPECKERS AND WRYNECKS. 7 



plate x. figs. 14 & 15, and plate xv. fig. i. tb) ; in the Powl (" Fowl's skull," plate lxxxvi. 

 figs. 4-6, i. tb) it lias two coils. In the same figure (7) the alinasal turbinal (al. tb) is 

 seen to form one nearly perfect coil. It is somewhat more like the inferior turbinal of 

 ordinary birds. In these things the Woodpecker is but little more specialized than a 

 Lizard or Sea-Turtle. 



Behind, the inferior turbinal (fig. 8) is continuous above with the aliethmoid (al.e), 

 which infolds itself, is pinched in and crenate, and becomes a rudimentary superior tur- 

 binal. This will be better seen in the thoroughly ossified parts of the adult (Plate V. 

 fig. 2, u. tb) : where the inferior turbinal ends, running into the front of the antorbital 

 plate, there a rudimentary " middle turbinal " is seen (ibid. m. tb). In the young bird 

 this section (Plate I. fig. 8) shows the termination of the nasal floor (n.f), curving 

 upwards to the partially ossified " perpendicular plate " (p.e) ; the nasal nerves (n. n), 

 the palatine {pa), the nasals, frontals, and nasal processes of the prsemaxillaries {n,f, n.px) 

 are also cut through, and a good view is obtained of the extent and relations of the 

 " maxillo-palatine processes" (mx.p). The condition of the nasal floor in this section 

 is preparatory to a remarkable metamorphosis, to be described hereafter. The adult skull 

 and face (Plate II.) can now be interpreted, notwithstanding the mixture there is in it 

 of arrest and of an unusual degree of metamorphosis. 



The palate (figs. 1 & 2) is a remarkable piece of basketwork ; and as in this species 

 ossification is intense, the nasal labyrinth brings in its many bony parts to add to the 

 complexity. The prseoral facial bones are thin and splintery, but are, notwithstanding, 

 very strong. The strongest part is the solid fore end of the prseniaxillary ; yet it is 

 quite hollow, forming scarcely any diploe except short side props at the junction of the 

 lateral with the lower plate. The head is the hammer, and the bony beak the helve, to 

 this curious combination of axe and chisel, the dense horny sheath forming an apt " suc- 

 cedaneum " for steel. The bindings on and interlacements of the facial plates and bars 

 have their meaning in this, that they carry off the jar from the brain of this plumy artisan. 

 Taking the parts in detail, we find that the " basipterygoid processes " (b.pg) are arrested, 

 and yet the pterygoids cleave close to the converging cranio-facial base. 



The cleanly cut groove formed by the pterygopalatine bars glides smoothly under the 

 rounded " parasphenoidal rostrum/' (r. b.s) ; this is a synovial joint : the rostrum ends in 

 a free style behind the oblique fore edge of the ethmoid, which spreads into two small 

 wings (figs. 1, 2, 3, r.b.s, p.e). The " notch " from being small and kidney-shaped 

 (Plate I. fig. 3, c.f. n), has grown into a very large nearly closed fenestra, which runs 

 forward to near the end of the septum. Thus the septum nasi (Plate II. fig. 3, s.n) is 

 reduced to a sharp bony keel running down a short way below the double sac ; and the 

 trabecular remnant, with its stunted praenasal beak (p.n), has an equally low crest. 

 One third of the trabecular bar is absorbed entirely behind; and scarcely half the 

 remainder is ossified by its centre ; the rest is a continued growth of bony matter from 

 the " septum" and the " trabecular cornua " (fig. 1, s. n, c. tr). The "notch" formino' 

 the cranio-facial hinge does not run through ; it is arrested earlier than in the Gal- 

 linaceous birds (" Powl's Skull," plate lxxxvi. fig. 14) ; and being anchylosed to the 

 ethmoid, the face sits more stiffly on the head than in most birds. The palatine process of 



