404 PROF. T. JEFFEEY PAEKER ON THE CRANIAL OSTEOLOGY, 



relations, but is proportionally much longer and more slender ; it articulates laterally 

 with the maxillo-palatines. In Dromceus it is also forked behind, but its anterior end is 

 expanded into a thin, flat plate, which articulates with the maxillo-palatine and is under- 

 laid by the palatine process of the premaxilla. In Bhea it is deeply forked in front, 

 each limb of the fork being underlaid by the corresponding palatine process of the 

 premaxilla. In Struthio it is flattened anteriorly, and on each side presents a facet for 

 articulation with the maxillo-palatine ; althougli shorter than in the other Eatitse, it is 

 considerably longer in the specimens in the Otago Museum than in Huxley's figure, 

 reaching as far forward as the anterior end of the nasals, and its forked posterior 

 end being connected on each side by ligament with the corresponding palatine. 



In the characters of the palatines also Apteryx is the nearest ally of the Dinornithidte. 

 Ill it they are short bones, about the same length as the vomer, and having much the 

 same twist as was described above iu the Moas. They are also expanded posteriorly, 

 where they unite with the vomer and pterygoids, and are overlaid in front by the 

 maxillo-palatines. Each is, however, clamped along its whole lateral edge by the long 

 palatine plate of the maxilla, and does not reach so far forward as the palatine plate of 

 the premaxilla. In Struthio the palatines are long, flat rods, their posterior ends 

 expanded for union with the pterygoids, and their anterior ends passing ventrad of the 

 maxillo-palatines and reaching nearly as far forward as the anterior end of the vomer. 

 In Rhea, Lrommus, and Casuarius the palatines are short, thin plates, more or less 

 curved, which pass from the pterygoids behind outwards and forwards to the palatine 

 processes of the maxillae ; they are not ankylosed with either the vomer or the 

 pterygoids in the Rhea and Emus in the Otago Museum, but are firmly united to 

 both in Casuarius galeatus. 



The pterygoid is a rod-shaped bone in all but Struthio, in which it is expanded in 

 front. Without the opportunity of examining good specimens of adolescent skulls, it 

 is impossible to enter into a detailed account of the modifications of this bone in the 

 various genera. 



In all the other Ratitse except Apteryx, the head of the quadrate resembles that of 

 the Moas, bearing an elongated oval articular surface broader at its lateral than at its 

 mesial end, and showing no trace of division into two facets. In Apteryx, as I have 

 pointed out elsewhere (24), the quadrate is practically double-headed ; the details of its 

 form are, however, subject to considerable variation. In an adult A. oweni, the mesial 

 end of the head bears a very distinct, nearly circular surface for articulation with the 

 facet furnished by the pro-otic and exoccipital (Plate LXII. fig. 69) ; passing outwards 

 from this it narrows considerably and at its lateral end is greatly expanded, forming a 

 surface, very convex from before backwards, for articulation with the concave surface 

 furnished by the squamosal and alisphenoid. In an adult A. australis there is a 

 perfectly distinct facet on the anterior surface of the outer end of the head for articu- 

 lation with the alisphenoid ; in another specimen of the same species the usually distinct 



