NEW GUINEA, BY C. W. DE VIS M.A. 



129 



It will now be only necessary to point out how and in what 

 direction the fossils differ from the corresponding bone in the 

 crowned pigeon, Goura coronata : but to extract from the former all 

 the information possible it will be well to add another term of com- 

 parison derived from the rasorial order: taking as its representative 

 the common low], Gal his. 



Determinative characters : — Proximal articular surface. In 

 the general proportions of this surface and in the relative depth of 

 its ccto — and endocondylar cups the three bones collated differ but 

 little — but the intercondylar eminence forming the rotular tongue is 

 in Goura broader and more symmetrically convex than in Gallus, 

 and in this feature the fossil is distinctly rasorial. In Gallus the 

 inner edge of the endocondylar cavity is rounded off posteriorly, in 

 Goura it is angularly produced — here on the other hand the fossil 

 shows as distinctly its affinity with the pigeon. The calcaneal pro- 

 cess of the fowl is elongate and consists of two parallel ridges, the 

 outer one the lower but well developel — in Goura the process ig 

 short and lias but one ridge, an outer one being hardly perceptible — 

 the fossil has also a short process but diverges towards Gallus in 

 hav Dg an outer ridge in an intermediate grade of size. The 

 proximal end of the principal ridge of the process in the fowl is 

 rounded off — in Goura it becomes pointed and somewhat unciform 

 by upward extension — such is its form but less pronounced in the 

 extinct bird. The whole process is much more exserted from the 

 shaft in the pigeon than in the foul, and and in this respect again 

 the fossil presents an intermediate condition, but a contra-in lication 

 is given by the intracalcaneal canal, relatively much larger than in 

 Goura in which again it is larger than in Gallus. In Gallus the 

 edge, of the shaft as it ascends fro^i the rim of the endocondylar 

 articulating surface diminishes very gradually in thickness and 

 the space between it and the short calcaneal process is consequently 

 much less concave than in Goura in which the edge of the bone 

 thins off suddenly and allows greater depth and width for the con- 

 cavity between it and the longer process — in this it is quite con- 

 formable with the fossil. On the palmar side ot the shaft the 

 the calcaneal process of the common fowl subsides gradually, in 

 strong contrast with its sudden subsidence in Goura, but in rather 



