160 SKELETON OF THE SHEEP 



BONES OF THE THORACIC LIMB 



The scapula differs chiefly from that of the ox in the following points : The ver- 

 tebral border is longer and the neck narrower. The spine is less sinuous. The 

 glenoid cxtremitj^ is relatively long, since the tuber scapulae is connected with the 

 rim of the glenoid cavity. The subscapular fossa is more extensive. 



The humerus is relatively longer and more slender than that of the ox. The 

 anterior part of the lateral tuberosity is blunt and less incurved, while the posterior 

 part is small. The deltoid tuberosity is nearer to the proximal end and is less 

 prominent. 



The bones of the forearm are relatively longer than those of the ox. The 

 radius is a little more curved than that of the ox, and its dorsal surface is more 

 regularl}^ rounded. The shaft of the ulna is more slender, especially in its distal 

 half; its fusion mth the radius occurs later and is usually much less extensive than 

 in the ox. 



The carpal bones resemble those of the ox except in size. The accessory is 

 long and less tuberous. 



The large metacarpal bone (Mc. 3 + 4) is long and slender. The lateral small 

 metacarpal bone (Mc. 5) is often absent or is represented by a ridge on the large 

 metacarpal. 



The phalanges of the chief digits are relatively long and narrow. The third 

 phalanx in particular is much flattened on its abaxial side, so as to form a prominent 

 dorsal border. Of the proximal sesamoids, the abaxial ones are compressed from 

 side to side, and the axial ones from before backward. The flexor surface of the 

 distal sesamoids forms a shallow groove, not divided by a ridge. The accessory 

 digits usually have no phalanges. 



BONES OF THE PELVIC LIMB 



The OS coxae differs greatly from that of the ox. The long axis of the ilium 

 is almost in a line with that of the ischium. The gluteal line appears as a ridge 

 which is nearl}' parallel with the lateral border. The tuber coxa; is only slightly 

 thickened, and the tuber sacrale is pointed. The crest is concave medially, convex 

 laterally. The shaft is relatively long and is flattened laterally. The superior 

 ischiatic spine is low and everted. The pubis resembles that of the ox, but its an- 

 terior border (pecten) is thin and sharp. The ischium slopes downward and back- 

 ward, and forms a much larger angle with its fellow than in the ox. The lesser 

 sciatic notch is very shallow. The tuber ischii is flattened and everted; it bears a 

 long, blunt-pointed lateral process, and a ver}^ short and blunt dorsal prominence. 

 There is a very low ventral ridge on the symphysis. The latter is not usually com- 

 pletely ossified, even in old animals. The acetabulum is further back than in the 

 ox, and is relatively larger and deeper; it has a deep notch posteriorly. The 

 pelvic inlet is very oblique, so that a vertical plane from the anterior end of the 

 symphysis cuts the first coccygeal vertebra. The brim is elliptical; the conjugate 

 diameter is about five inches (ca. 12 cm.), and the transverse about three and a 

 half to four inches (ca. 9.5 cm.). The floor of the pelvic cavity is wide and shallow 

 as compared ■svith the ox, and the pelvic axis inclines downward posteriorly. 



The shaft of the femur is slightly curved, the convexity being anterior. A dis- 

 tinct line separates the lateral and posterior surfaces. The supracondyloid fossa 

 is very shallow. The head has a shallow fovea and the neck is distinct. The tro- 

 chanter major is little higher than the head. The ridges of the trochlea are similar 

 and parallel, but slightly oblique. 



The tibia is long and slender, but otherwise resembles that of the ox. The 

 fibula has no shaft, and its proximal end is represented by a small prominence be- 



