REGIONAL ANATOMY ll 
Fic. 4.—THirp Paatanx or Os PEpis (PoSTERO-LATERAL VIEW). 
1, Anterior or laminal surface ; 2, preplantar foramen; 3, preplantar groove ; 
4, basilar process of the wing ; 5, retrossal process of the wing ; 6, foramen 
caused by the ossifying together posteriorly of the basilar and retrossal 
processes. 
Fig. 5.—Tuirp PaaLanx or Os Peps (VIEWED From BELOW). 
1, Plantar surface ; 2, plantar foramen and plantar groove ; 3, semilunar crest ; 
4, tendinous surface ; 5, retrossal processes of the wings. 
