1888.] Structures found in the Skull of JBlrds. 



401 



forwards towards the palatine, but does not coalesce with it, except 

 in Banodon sibiricus* 



This endoskeletal cartilaginous palatine, with its peduncle and fore 

 and hind ray or crus, appears in several kinds of birds, in addition 

 to their normal par osteal palatine — a mere membrane bone, as in 

 Reptiles and Mammals. 



This vestige or remnant remains in the adult ; it is of no apparent 

 use, and occurs in the Families in the oddest way ; sometimes, how- 

 ever, it is present in all the members of some particular Family-group, 

 as for instance in the Musophagidse or plantain- eaters (Musojohaga, 

 Schizorhis, and Gorytliaix).\ 



My own later researches show it well in the Oil Bird (Steatornis 

 caripensis) and in the Green Tody (Todus viridis) ; but it is well 

 developed in Scythrops (see i Linn. Soc. Trans.,' ser. 2 (Zool.), vol. 1, 

 plate 23, figs. 4 and 3, o.u.) 



In that nearly extinct Neotropical type, Steatornis, this curious 

 partly ossified remnant has the three crura, all well marked, and 

 their morphological meaning is evident ; albeit the whole piece is so 

 small and feeble that it can serve no purpose in the solid palate of 

 that remarkable bird. 



To show how unexpectedly this remnant exists, and does not exist, 

 I will give a list of the Birds in which it has been found in a seg- 

 mented state as a distinct bony element of the face ; it often shows 

 itself as a mere process of the ecto-ethmoid : I do not include those 

 birds in the list. 



Mot*cillayarrelli} Motacim ^ 



Budytes rayi J 



Todus viridis. Todidaa. 



Steatornis caripensis. Steatornidas. 



Schizorhis "| 



Musophaga > Musophagidaa. 

 Corythaix J 



Dicholophus. Dicbolophidaa. 

 Procellaria ~) 



wiT ^ IProcellaridse. 



Thalassiaroma ( 



Diomedea, 8f c. J 



Lams, var. spec. Laridse. 



Tachypetes. Tachypetidse. 



Another more partial remnant is seen in the CoracomorphaB or 

 Passerine birds generally, which together make up nearly half the 

 number of known birds. 



In my paper " On the Skull of the Urodeles " (' Phil. Trans.,' 1877, 



* See Wiedersheim, 1 Kopfskelet der Urodelen,' Leipzig, 1877, Plate 5, figs. 69, 70. 

 f See Eeinhardt, ' Om en hidtil ukjeiidt Knogle i Hovedskallen bos Turakoerne 

 {Musophagides, Sundey.) ' Copenhagen, 1871, Plate 7. 



