OSTEOLOGY. 97 



for ligamentous attacliment, more especially the anterior 

 for the middle anterior annular ligament for which there 

 is a slight depression. The external surface presents a 

 groove running from below upwards, separating the rough- 

 ened anterior and posterior parts. This leads upwards to a 

 roughened line which tends to separate the upper surface 

 into two articulatory parts and after reaching the inner 

 surface curves in a direction backwards. Thus at the pos- 

 tero-external angle it cuts off a convex, ovoid facet sloping 

 obliquely downwards, outwards, and forwards for union 

 with OS calcis. The anterior articulatory facet is divided 

 into two parts, the outer largest, quadrilateral at the 

 antero-external angle of the surface, slanting slightly 

 outwards and forwards, continuous along its internal 

 margin with the inner part which is pyriform (broadest 

 posteriorly) for union with astragalus. It does not reach 

 to the anterior margin of the bone, but along its inner 

 edge blends with a pyriform facet, with its base anteriorly 

 placed at the antero- superior angle of the internal surface 

 for cuneiforme magnum. The inter^ial surface at its 

 postero- central part has a prominence, smooth and articu- 

 latory both above and below. The superior facet looks 

 upwards and inwards meeting os cuneiforme magnum. 

 The inferior, downwards and inwards for cuneiforme 

 medium. At the antero-inferior angle is a facet elongated 

 from before backwards continuous with one for metatarsi 

 magnum on the inferior surf ace, it articulates with medium. 

 The space between these is roughened for ligamentous 

 attachment, but around the posterior and superior part of 

 the last mentioned facet is a deep smooth groove extending 

 to below the articulatory prominence posteriorly, through 

 which the communicating branches between the anterior 

 and posterior tibial veins run. The inferior surface presents- 

 two facets, one at the antero-external angle, the other at 

 the postero- external angle for union with os metatarsi 

 parvum externum. The former is largest and continuous 

 inferiorly with a surface sloping upwards and inwards for 

 metatarsi magnum, which joins one on the inner surface 

 for cuneiforme medium. The superior surface is occupied 

 by a smooth articulatory surface elongated from before 

 backwards with the greater portion of which os calcis 

 comes in contact. 



The remainder of the bones of the hind limb resemble 



7 



