316 PROF. W. K. PAliKER ON .IIGITHOGNATHOUS BIRDS. 



and an equally straight but slenderer pterygoid (pff) ; between these the parasphenoid 

 (pa.s) is thick and without basipterygoid processes. Above the parasphenoid the thick 

 perpendicular ethmoid (^>. e) and the septum nasi are but parts of one continuous 

 orbito-nasal septum, as in the Tinamidse; for here the cranio-facial cleft is as 

 imperfect as in Tinamus variegatus (" Ostrich Skull," pi. xv. fig. 8, c.f. c) : even in that 

 species there is a considerable " notch." There is this carinate character, however ; and 

 that is, that the ossification stops at the usual place, and the bony matter does not pass 

 from the ethmoid, forwards, to ossify the nasal septum {op. cit. pi. xv. fig. 10,^. e, s. n). 

 Yet in respect of this almost undivided orbito-nasal septum, this ground-bird is one of 

 the most struthious of the carinate types ; it has, however, a small oblique fenestra in 

 front of the " meso-ethmoid " (fig. 10, c.f. c). 



The anterior part of this vertical plate in GmUaria is principally hyaline cartilage, 

 unchanged ; but abeve, a septal bone appears ; and below, a very frequent centre, the 

 " postseptal " or trabecular bone {tr) has commenced. This is the bone which, in many 

 typical Carinatse, forms the postero-inferior angle of the septum nasi ; and it bounds 

 the great " hinge " in front. Here it is seen midway between the ethmoid and the 

 fore part of the huge, deep septum. The symmetrical parts of the nasal labyrinth are 

 supplied with arrested centres of ossification ; on the inner face of the alinasal turbinal 

 (figs. 8, 9, a. th) there is a long, lanceolate tract of endostosis ; and on the base of the 

 posterior third of the left alinasal turbinal there is a patch (fig. 9, a. tl) both ectosteal 

 and endosteal. 



On the outer face of the " inferior turbinal " there is a large wedge-shaped, well- 

 ossified tract, with its base behind ; and on the outer face of the upper turbinal there is 

 a squarish bony tract, the size of that on the inferior turbinal. Also the posterior half 

 of the alinasal wall is ossified as in Gecinus viridis and many of the " Coccygomorphee." 

 All these bony centres are of great interest ; for they represent the various commence- 

 ments of the continuous bony growths seen in this region in such birds as Gymnorhina, 

 Artamus, and also in birds that lie beyond the passerine boundaries. 



Perhaps in the whole range of ornithic morphology there is no character more to be 

 depended upon than that cleft in the trabecular commissure which, growing upwards, 

 divides also the anterior nasal from the true olfactory region. Yet in Pitta and Grallaria 

 this is almost absent, and their intense struthiism is combined with Eegithognathism 

 of the highest degree. The vomerine moieties have grafted themselves upon the end of 

 the alinasal turbinals (fig. 9, a. tb, v); and, on each side, a septo-m axillary {s.mx) supple- 

 ments this peculiar metamorphic union of diverse parts. The thick, massive upper 

 lobes of the vomer evidently owe their great size both to the alinasal turbinals and to 

 the proper vomerine cartilages. As in Pitta, the rest of the vomer is flat, and the crura 

 are near together ; they coalesce with the coiled ethmo-palatine. 



The next arch is extremely like that of Pitta (see figs. 6 & 8) ; the pterygoids {pg), 

 however, are slenderer, and the postpalatine keels longer : these are separate from the 



