30 * EQUINE ANATOMY. 



THE PHALANGES. 



THE FIRST PHALANX (OR PASTERN BONE). 



T\i^ first phalanx lies between the principal metacarpal and the 

 second phalanx, and has a shaft and two extremities. 



The shaft has an anterior convex stirface, a posterior, flattened 

 and rough, and two thick borders. 



The tipper extremity has two articular depressions, separated by 

 a ridge. 



The inferior extremity has two condyles, separated by a groove 

 and laterally two Hgamentous depressions. 



SECOND PHALANX (OR OS CORON/E). 



The second phalanx is a short bone with two articular depres- 

 sions above, two articular processes below, an anterior face with 

 imprints, and a posterior face with a transverse gliding surface. 



Articulations. 



First phalanx, third phalanx and navicular done. 



THIRD PHALANX (OR OS PEDIS). 



The third phalanx supports the hoof and anterior limb. It is 

 somewhat pyramidal in shape, and is divided into thj-ee faces, 

 three angles, and two lateral borders. 



The anterior face is perforated for vessels and shows laterally 

 the pre-plantar fissure between the basilar and retrossal processes ; 

 the patilobe eminence below the fissure. 



The superior face shows — 



Two articular cavities separated by a ridge, for the second 

 phalanx. 



The inferior (or so la?-) face shows — 



A flat surface below, on which the foot rests, a curved fine, the 

 semi-lunar crest, and laterally two channels, the plantar fissures, 

 opening into a cavity in the interior, the semi-lunar sinus. 



The superior border has its convexity forward, and shows the 

 pyra7nidal eminence for muscular insertion. 



The inferior border is convex and perforated by foramina. 



The posterior border shows a facet for the navicular bone. 



The lateral angles show two posterior projections, a superior, 

 the basilar, and inferior, retrossal processes. Between the two is 

 the origin of the pre-plantar fissure. 



