ANCODON GOEEINGEI. 187 



which beneath this point becomes much more slender, expanding again a little towards 

 the distal articulation. The distal articulation is quadrate in outline, and its outer border 

 is occupied by a large facet for the fibula, looking outwards and downwards. The 

 groove for the outer half of the astragalar articulation is both broader and shallower 

 than the inner, which is very narrow and is deepened anteriorly by the presence of a 

 strong internal malleolar process. The dimensions (in centimetres) of this specimen 

 are : — 



Extreme length 40-5 



Width of proximal end 10 



„ distal end 6'2 



Antero-posterior length of distal articulation 4-2 



Width of shaft at narrowest 3-8 



Presented by the Egyptian Government, 1904. 



C. 8899. A similar right tibia, of which the dimensions (in centimetres) are : — 



Extreme length 39 



Width of proximal end . . . 10 



„ distal end . . . 5'4 



,, shaft at narrowest 3'7 



C. 9313. Right tibia of rather more slender form, probably of a different species. A very 

 prominent thin internal malleolus. The dimensions (in centimetres) are : — 



Extreme length 41 



Width of proximal end . 9 



„ distal end .' 4'6 



„ shaft at narrowest 3-4 



M. 8864b. Right tibia, similar to M. 8864 a, but wanting the proximal epiphysis. 



Presented hy the Egyptian Government, 1904. 



M. 8507. Right astragalus (text-fig. 61). In this bone the relative heights of the outer [o.c.) and 

 inner condyles [i.e.) of the proximal trochlea are about as in astragali of Ancodon 

 (JPyopotamus) from the Isle of Wight, but the outer condyle is rather more massive. 

 In the distal trochlea the cuboid surface {cub.) is relatively rather wider, and the keel 

 between it and the navicular surface (wazi.) less prominent than in the European species. 

 The sustentacular articulation {sus., sus.') seems to be closely similar to that described by 

 Scott * in the American species — that is to say, it is divided into an outer facet {sus.) , 

 nearly flat from side to side, but convex from before backwards and looking towards 

 the plantar surface, and an inner {sus.'), in this case much narrower, facet, which 

 does not extend quite so high up proximally, but further distally, the distal portion 

 being an almost distinct rounded surface; this internal portion of the sustentacular 

 articulation looks towards the outer and plantar surface. Of the outer calcaneal facets 

 the proximal one {ect.) is divided by a deep depression into proximal and distal portions, 

 of which the latter is. borne on a strong prominence and looks mainly towards the 



' The Structure and Eelationships of Ancodus," Journ. Acad. Nat. Sci. Philad. [2] vol. ix. pp. 482-83. 



2b2 



