THORACIC LIMBS 



539 



VARIATIONS IN FORM AND DEVELOPMENT. 



The scapula exhibits variations in form, due principally to modifi- 

 cations in the relations between the length and the breadth. In some 

 cases the supraspinous fossa more nearly equals the infraspinous fossa. 



The superior angle is occasionally indistinct and rounded, but in a 

 small proportion of specimens it is as distinct as the inferior angle. 



The spine varies slightly in the angle it makes with the surface of 



