PELVIC LIMBS 763 



part is arcuate, the middle part emarginate, and the plantar end either 

 straight or slightly emarginate, and meets the tibial border at a more 

 or less defined plantar angle. The tibial border runs more vertically 

 than the fibular, and is arcuate or angular above and deeply emarginate 

 below the middle. The lower part is arcuate, passing downward and 

 to the fibular side to form the plantar angle. 



The entire surface is smooth, and faintly concave from above down- 

 ward ; it articulates with a corresponding triangular proximal surface 

 of the base of the third metatarsal. 



The plantar surface (Fig. 587) consists of the plantar surface of 

 the hook-like process. This is oval and twice as long as wide ; the 

 long diameter passes obliquely from the proximal to the tibial side. It 

 is convex, and gives attachment to ligaments. 



FIG. 580. 

 Dorsal Side. 



With Second Metatarsal. 



With Meso-^- f , gg^ n , 

 Side. cuneVurm.^^^^fcV Disi(d ^^ 



Hook with Groove 

 for Tendon of 



PERONEUS LONGUS. 



Plantar Side. 



LEFT ECTOCUNEIFORM, TIBIAL SURFACE. 



The tibial and fibular surfaces are very similar, and can be dis- 

 tinguished only by close attention to several small details. They are 

 nearly square ; the proximal border is shorter than the distal, and the 

 dorsal border is shorter than the plantar. The dorsal border is some- 

 what rough ; the proximal and distal borders are sharply defined, 'and 

 the plantar border is not well marked, because for most of its length 

 it gives support to the base of the plantar hook-like process of the 

 bone. It can be located by drawing a line between the proximal and 

 distal plantar angles. The hook consists of a base and a head. The 

 base is applied to the plantar border, which, owing to the prismatic 

 form of the bone, is a border common to the tibial and fibular surfaces 

 and represents all there is of a true plantar surface. The base of the 

 hook is compressed from side to side and narrows from before backward 

 to form a neck, whereon is placed the head, which is wider than the 



