194 MR. W. K. PARKER ON THE OSTEOLOGY 



from the Fowl to the Emeu'. In about three-fifths of the genera of birds this articu- 

 lation of the side of the pterygoid with the outstanding anterior pterygoid process 

 only exists in the embryo, or at any rate only in the fledgeling. The articular pro- 

 cesses are very feebly marked as thickenings of the cartilages in the Old-world Crows, 

 and vanish after the middle of incubation ; traces of them can be generally seen up 

 to the time of hatching at least ; and in many birds they exist throughout life on 

 the basisphenoid, generally as recurved prickles, e. g. in Gymnorhina, Ortygometra, &c. ; 

 and a large prickle of this nature is well shown in Strickland and Melville's beautiful 

 plates of the Dodo : this is on one side ; on the other the arrested process is a mere 

 elevation. 



The palatines of the Syrrhaptes (PI. XXXVI. fig. 1) are but a step in advance of 

 those of the ordinary " Struthionidse " (PI. XLII. fig. I, pa.); but they have, as in 

 Tinamus (PI. XL. fig. 1), the peculiarly ornithic premaxillary portion of the palatine 

 present, as a mere thread of bone, however. Still, on the outer edge of the Syrrhaptes 

 palatine there is a faint groove answering to the well-made, highly ornithic groove of 

 the palatine in the Pigeon and Plover (PI. XXXVI. figs. 1 & 6, pa.) — a groove formed by 

 the development of two keels or crests on the posterior third (or essential part) of each 

 palatine-. There is no vomer in the Syrrhaptes to tie the two palatines together ; and 

 this is a sudden assumption of a columbaceous character. Yet, in spite of this, the 

 extremely wide separation of the palatines, and the consequent width — extreme width — 

 of the middle nares shows how close this bird is, not only to the Ostrich, but also to 

 the Reptiles. 



In the " Struthionidse " the mucous membrane of the palate has three large slits, one 

 mesial and behind, for the two Eustachian trumpets to open into ; and two somewhat 

 further forwards, which converge considerably towards their anterior end : these are 

 the middle nares, separated by the mucous membrane covering the large thick vomer. 

 In typical birds these three form one large vestibular slit, as is well shown in Macgil- 

 livray's figure of the Buzzard's head (Brit. Birds, vol. iii. pi. 17. fig. 1). 



In Syrrhaptes the middle nares are as wide as in the Ostriches ; but in the dry skull 

 they are only separated by the huge basisphenoidal rostrum, and by the laminje of the 

 palatines that embrace it (PI. XXXVI. fig. 1 ). The interorbital septum of the Syrrhaptes 

 (fig. 4) is intermediate between that of the Grouse and the Pigeon ; better than in the 

 latter, but with more membrane than in the former. As in the Pigeon, Plover, and 

 Hemipodius (Pis. XXXIV. XXXV. & XXXVII.), the posterior part of the middle ethmoid 

 above, and the body of the presphenoid which articulates and ultimately coalesces 



' In the Humming-bird the anterior pterygoid processes abut against the palatine ends of the pterygoids ; so 

 that they present the most perfect contrast to what is seen in the Ostriches. 



^ In some pluvialine birds there is a retral process to the palatine, the rudiment of the " os transversum " of 

 the Passerine, Alcedine, Psittacine, and Caprimulgine groups. This important reptilian bone is, in these birds, 

 distinct, tirst as cartilage, and then as bone : it coalesces with the palatine. 



