358 Mr. A. H. Garrod on the 



than in most birds,, and there is only a slight movement possible 

 of the upper jaw on the head proper. The interorbital septum 

 is thick and nearly complete, supporting a median protrusion 

 on the front of the skull which is so considerable as to throw 

 the free extremities of the hyoid bones to one side or the other, 

 thus causing the skull to be slightly un symmetrical. Further, 

 the axis of the upper beak is peculiarly low, being continuous 

 with that of the basicranium ; and this results from the lowness 

 in position of the points of junction of the superior processes of 

 the prsemaxillse with the frontal region of the skull, which 

 renders the angle between the beak and skull less obtuse than is 

 generally the case. In those birds in which there is con- 

 siderable hinge-motion of the upper beak on the head, as in the 

 Parrots, the basispheuoid rostrum is generally long and of uni- 

 form thickness for some distance, and the conjoined palatine 

 bones, with the vomer between them and tlie pterygoids articu- 

 lated behind, form a longitudinal flange along the upper surface 

 of the median junction, which runs backwards and forwards on 

 the rail formed by the basispheuoid rostrum during the move- 

 ments of the beak. In the Woodpeckers any considerable 

 articulation of this kind would reduce the value of the head as 

 an axe ; consequently the posterior ends of the palatine bones are 

 not well developed, and they scarcely unite in the middle line, 

 while further forwards the vomer is not seen in the maxillo- 

 palatine region, and these latter bones also are only slightly 

 developed. A similar tendency among Passeriniform birds to 

 the reduction of the vomer in front is found, combined with a 

 complete absence of the maxillo-palatines, in Menura ^. 



Professor Huxley, in his paper " On the Classification of 

 Birds" t, has entered into considerable detail respecting the 

 Woodpecker's palate, and from not finding a vomer present, and 

 observing the peculiar longitudinal bony spicula connected with 

 the inner edges of the palatine bones, opposite to and behind 

 the fenestrse they assist to enclose, is led to think that these 



* Since the above has been in print I find that the maxillo-palatines 

 are not absent in Menura, but are long and slender, diifering somewhat 

 from the ordinary passerine type, but separate from one another and from 

 the vomer. 



t Proc. Zool. Soc. 1867, pp. 415-472. 



