174 MR. W. K. PARKBE ON THE STRUCTUEB AND 



the simple, but thoroughly differentiated and typical " Grallaj" is extremely interesting, 

 because in the next subgroup (the Tinamous) the characters of special types begin to 

 break out and to become unmistakeable ; so that these birds seem to have something 

 mixed and monstrous in them, a very patchwork of ornithic qualities. The nasal pro- 

 cesses of the intermaxillaries of the Apteryx continue distinct (at this stage) for an 

 inch; combined, they form a strong bar more than 3 lines thick; then the solid part 

 is extremely short, and being deeply grooved, looks as though the nostrils were sub- 

 terminal; the nasals flank the nasal processes of the intermaxiUaries for nearly half 

 their length posteriorly. The angle of the dentary plate of each intermaxillary reaches 

 two lines further backwards than the nasal process. 



Plate 2, figs. 3 & 5, show the five usual splints and the "articulare;" the symphysis 

 is three-fifths the length of the mandibles ; and the splenial pieces, which are 3 inches 

 long, have nearly half their length in front of the divergence of the rami. 



The OS hyoides (pi. 2. fig. 8) agrees with what I have described in the Emu and Casso- 

 wary, viz. a basi-uro-hyal piece pointed at both ends, and a two-jointed pair of first 

 branchials ; but the flattened cerato-hyals are not shown in this figure. 



In the descriptions that follow I shall make use of these observations upon the skull 

 of the young Apteryx ; and a comparison of the Tinamous with the other " Struthio- 

 nidae," without the Apteryx, would have been very imperfect. Of all known birds, the 

 Apteryx and the Cassowary appear to me to be least ornithic and most generalized ; 

 the leaning of the latter is evidently most to the Gallinacea3, that of the former to the 

 long-billed " Pluvialinse ; " but the Cassowary and the Apteryx seem to approach equally 

 near to the Mammal on one hand, and to the Eeptile on the other. 



Tinamus variegatus and robustus. 



I have in another place (Zool. Trans, vol. v.) described the skull of Tinamus robustus, 

 but there are points of its structure which must be described here, in comparison witli 

 that of T. variegatus. In the paper just referred to I have given at length my reasons 

 for placing these birds with the " Struthionidse ; " we shall find as we proceed that what- 

 ever tendencies to affinity with other groups may be discerned in the larger Ostriches, 

 yet these declarations for special types are but feebly uttered, when compared with what 

 is manifested in the " Tinaminse." The Fowl and the Plover strive for mastery here, 

 but the nature of the bird has to be drained through several generic " limbecks " before 

 it becomes pure and simple enough to be truly gallinaceous or truly pluvialine ; the 

 Sandgrouse and the Hemipods, and even the Megapods, all intervene between the evi- 

 dently heterogeneous Tinamou and the true Fowl and Plover*. 



The first point to be noticed in the Tinamou, the occipital condyle (Plate XV. fig. 2, 

 oc), is a departure from what we have seen in the " Struthionidae ; " and although this 



* Now the hand of Darwin is not with me in all this ; nor need the patient positive observer be anxious as 

 to what these things will grow ; the truth of the matter being ascertained, let come of it what will, we are not 

 careful to answer in this matter. 



