PROF. W. K. PAEKEE ON ^GITHOGNATHOUS BIRDS. 295 



Hemipod (fig. 9) it is much more like that of the Ostrich family ; and this trabecular 

 underbearer of the ethmoid (fig. 11, ja.e) is swollen and spongy as in the " Eatitse." 



The cranio-facial " hinge," however, is as perfect as in the Fowl ; and the rest of the 

 coalesced trabecular bar is unossified and forms the lower edge of a feeble septum nasi 

 (s.n). As in the Crow and many of the " CoracomorphaB," the trabecular base of the 

 septum is alate in its middle region (fig. 4, s. n, tr). The prsemaxilla (figs. 1, 2, 9, 

 10, 11, ^.r), even in the old bird, remains but little different from what is seen in the 

 ripe chick of the Fowl (" Fowl's Skull," pi. 84), having a form common to Pigeons, 

 Sandgrouse, and Hemipods. 



The body of the bone is of small extent, the dentary processes thin and splintery 

 (d.j)x), the palatine processes (fig. 1, p.px) very slender styles, such as we everywhere see 

 in the feebler Coracomorphse ; and the early ankylosed nasal processes (fig. 2, n.px) 

 are flat, splintery, and struthious. These processes retain their outline in the adult (fig. 10) 

 after they have coalesced with their surroundings. But the greatest marvel in this bird's 

 face is the peculiarities of its vomer, both in form and development. Very strange in 

 form is the one figured by me in my earlier paper (" On the Gallinaceous Birds," &c. 

 pi. 34. fig. 1, v), where it is described as the " little broad vomer," which is convex 

 anteriorly, with a short horn at each angle, and ending behind in a slight style on each 

 side for attachment to the palatine '. 



This species was not determined ; but it had the most coracomorphic vomer of the 

 three worked out by me ; compare that figure with those of the young Crow (Monthly 

 Micr. Joum. Nov. & Dec. pis. 36-39, v). 



But dry, adult specimens give no idea of the true meaning of this vomer, which is com- 

 posed of four osseous and two cartilaginous elements, as in the huge " family," or 

 rather " order," of the Coracomorphse. Amongst the birds that have uprisen from the 

 Tumicine " stratum," the Plovers have a symmetrical vomer, formed of two sickle-shaped 

 pieces, in indifierent tissue. The Sandgrouse and Pigeons, as far as 1 have seen, have no 

 vomer (" GaUin. Birds," pis. 36 & 37) ; but the true Grouse, and all the "Alectoromorphse " 

 proper, have an azygous vomer formed in indifferent tissue (op. cit. pi. 36. fig. 6 ; and 

 "Fowl's Skull," pi. 83. fig. 1, pi. 84. fig. 6, pi. 86. figs. 3, 4, 5, 10, 14, 15, and pi. 87. 

 fig. 5, v). 



Thus, starting from the truly struthious face of the Tinamou, with its immense 

 symmetrical vomer, we suddenly find ourselves in the very midst of vomerine modifi- 

 cations which are only a little more specialized even in types the furthest removed from 

 the base^. 



In the young of Turnix rostrata the broad part of the vomer (fig. 8, v) is very short, 



' The " praevomers " there spoken of are the true " maxillaries ;" the " prtevomerine " ossicles or " septo- 

 maxillaries " are the separated " horns " of the vomer, as I shall soon show. 



'' If the convenient fancy of our ornithic life-tree be kept in mind, to help the memory, then this tree must 

 be one of many branches, suddenly starting from the root. 



