908 THE OSTEOLOGY AND MYOLOGY OF THE DEATH ADDER, 



the internal is attached the internal pterygoid muscle, and a 

 very strong internal ligament which unites it posteriorly to the 

 articular bone below. The trochlear surface has its axis placed at 

 right angles to the long axis of the head. It is the shape of an 

 hour glass. The exterior portion is smaller and lower than 

 the interior, since the axis of the extremity runs outwards and 

 downwards. Both surfaces are convex from before back, while 

 two surfaces go to make up a concavity from side to side. Each 

 of the trochlear surfaces forms a semicircle, but the radius of the 

 internal is to the radius of the external as two to one. Above the 

 trochlear surface in front is a slight depression which receives the 

 " coronoid " process of the articular. 



The quadrate articulates with two bones, the squamosal, and the 

 articular, and is in connection with the columella and stylohyal. 

 This bone differs considerably in shape from the quadrate of 

 Python. In the latter it is quadrilateral, and the inferior 

 extremity is even broader than the superior. There is the same 

 evident twist, but the bone is for the most part composed of an 

 internal and external surface. The projection from the columella 

 is also much more marked in Fytlion. Comparing the size of the 

 skull of the two snakes, the quadrate of Acanthojyhisis much more 

 powerfully made than in Morelia or Python. In fact the 

 quadrate is the most stoutly made bone in the head. 



The Mandible. 



Os Dentate, Os Angulare, Os Articulare, Harting, Gegenbaur, 

 Hoffmann, Parker, Parker and Bettany, Owen, Wiedersheim. 

 Os Dentale : L'os dentaire, Cuvier ; Zahnstilck, Meckel ; Dentate, 

 Stannius. Os Articulare : Articulare, Cuvier, Stannius ; Gelenk- 

 stilck, Meckel. Os Coronideum : Comjolementa^-e, Gegenbaur ; 

 Kronstilck, Meckel; Coronoideum, Hoffmann, Parker and Bettany, 

 Parker; Complementare vet coronoideum, Stannius; Coviptementare, 

 Owen . Os Spleniale : S2)leniale, Parker and Bettany, Parker ; 

 Oi^irculare, Stannius, Gegenbaur, Owen, Harting, Hoffmann. Os 

 Supra-angulare : Suirra-angulare, Parker and Bettany, Gegen- 



