SKULL OF THE .aSGHTHOGNATHOUS BIEDS. 305 



great Pluvialine group, or a rounded notch as in the Passerines and Gallinacese 

 proper, is exactly intermediate, being lanceolate. It agrees very closely in 

 this respect with the small Hemipodius already described by me (Trans. Zool. 

 Soc. vol. V. pi. xxxiv. fig. 3). 



7. The bevelled shoulders of the vomer articulate with the maxillo-palatines, as 



in the Cotingidse and Formicariidse. 



8. It agrees with Hyloterpe, Pachycephala, and Cypselus in its " os uncinatum." 



It also agrees with the Hemipods in showing part of the bony ethmoidal plate 

 (fig. 5, e. etJi) between the forks of the nasal, but not to the same extent — not 

 as a swollen mass, but as a thin lamina, as in those birds generally that have 

 the nasal notch sharp. 



Pigeons, birds that stand immediately above Sand-Grouse and Plovers, and, although 

 of a higher type, are almost equally related to both those groups, have the same 

 structure '. 



The narrow frontal region between the eyes is deeply sulcate above; but the 

 Gallinaceous value of this character is immediately annulled by the presence of very 

 distinct super- and postorbital fossae for the nasal glands : in this thing it is contrary to 

 the Fowl tribe. The structui-e of the interorbital space, praesphenoid, orbitosphenoid, 

 and pars perpendicularis (p.s, o.s, pe) is in perfect harmony with the Gruinee and Plu- 

 vialine types of skull. 



But there is one thing in the relation of the lateral ethmoid to the palatine which 

 corresponds with that of both the Cuculinse and of cext^Jm Notogceal Passerines : a " pars 

 uncinata," like a small nipple, projects forwards and outwards close in front of the feeble 

 ascending ethmo-palatine spur (fig. 5, o. u, e.pa). This, to one familiar with the 

 development of the Batrachian skuU, is most interesting; and the two converging 

 points are the elements of the primordial commissure between the trabeculse and the 

 pterygo-palatine portion of the mandibular arch. This is the more noteworthy as 

 being in unison with the huge dilated vomerine and parasphenoidal bars, and the 

 distance between the pterygo-palatines. 



The relative feebleness of these bars is remarkable (fig. 1, pa, pg) ; but they are truly 

 ornithic and quite Gruine (see also fig. 6). The extreme shortness of the pterygoids as 

 compared with the palatines is almost an exaggeration of that which is normal in 

 Carinate birds. But the pterygoid of Thinocortis has become less than half its original 

 length by metamorphosis ; it originally reached the vomer ; and the new segment (meso- 

 pterygoid, mspg) has coalesced with the palatine. 



' I mention this to remind the reader how near some of the " Altrices " are to certain " Praecoees," and as aii 

 apology for any attempt to trace the Passerine rhizome. 



