THE SKULL IN THE WOODPECKERS AND WRYNECKS. 9 



mamillaries," small ovate-oblong patches of bone (figs. 1, 2, 5, m. s.mx). A single bone in 

 this region is not uncommon in Birds, as I have already shown. These apparently 

 azygous bones will be explained by a younger specimen. 



In this species (the Green "Woodpecker) the main septo-niaxillary piece rivals its 

 symmorph in many of the Lizard kind ; and when all the details of this instructive but 

 perplexing skull are mastered, I am confident that the term " saurognathous " for this 

 kind of palate will not be thought inappropriate. 



The nasal labyrinth is so intimately connected with the trabecular arch that its 

 description may well come in here. I have already shown its structure in the July bird, 

 and also the relation of tbe median part to the first arch. 



In this species the turbinals and alse nasi are endosteally ossified ; the alse project 

 strongly in front, and in infolding themselves form a remarkable boss on each side, 

 which is strongly attached to the fore part of the septum nasi by continuous ossification 

 (figs. 1, 2, 5, al.n, c.tr). These bosses are the trabecular cornua. The "alinasal 

 turbinal," coiled once upon itself (Plate V. figs. 6 & 7, al. tb), is of enormous size; the 

 " inferior turbinal," equally simple (Plate V. figs. 7 & 8, *. tb), is one fourth less. In a 

 front view of the antorbitals and perpendicular ethmoid (Plate V. fig. 2, p. e) we see the 

 " rostrum " of the " parasphenoid," the fore end of the median ethmoid, flat-faced below, 

 and growing into the aliethmoid above the elegant ear-shaped " superior turbinals " 

 (u. tb), the rudiments of the "middle" (m. tb), and scars where tbe inferior turbinals 

 (i. tb) have been broken away. The parts are intensely anchylosed ; but we can discover 

 the passages for the first and nasal branch of the fifth nerve (1, 5), the great size of the 

 " ectoethmoid," mounting to the top above, and sending backward a large " uncinate " 

 process below. The frontal bones (/), strongly roofing in the forehead, are thrown into 

 a solid ridge by the tips of the " cornua majora " (br. 1), which turn to the right side, 

 and he in an obliquely directed smooth groove. 



The second, or pterygopalatine arch (figs. 1, 2, 4) has a short posterior segment, or 

 pier, the pterygoid (pg). This bone is broad, inwardly bent, and bifurcate (Plate 

 III. fig. 7, pg) ; for it sends upwards and forwards a process, or muscular attachment, 

 behind the true mesopterygoid process (m.pg) : the latter does not become segmented 

 off ; and hence this bespeaks less metamorphosis than what obtains in a Passerine bird. 

 There is no " epipterygoid " process. The long, flat, elastic palatines {pa), are anchy- 

 losed to the dentary and palatine portions of the prsemaxillary, but not to any part of the 

 maxilla or their own splints. The " transpalatine " angle is aborted and obtuse ; the 

 inferior surface of the broad part of the bone is gently sulcate along its middle. This 

 broad partis of great extent, and ends in the slender " interpalatine " spine (i.pa), 

 which looks towards the free retral end of the palatine plate of the prsemaxillary, but does 

 not in this instance help it to enclose an oval space ; it may do so in very old birds. 



The postpalatine region is narrow, the bones attenuating suddenly ; and the " ethmo- 

 palatine" laminae (e.pa) are of very small extent, and have no spine, or only a rudiment 

 for attachment to the vomerine ligament ; the plate is fenestrate on the right side. The 

 commissure is finished by the endosteal mediopalatine (fig. 2, m.pa), a lozenge-shaped 

 bone, dagger-like behind. The palatine arch is seen to be fenced on its outer side by a 



SECOND SERIES. — ZOOLO&Y, VOL. I. C 



