982 THE OSTEOLOGY AND MYOLOGY OF THE DEATH ADDER, 



Fig. 1. — The parietal bone. The superior surface is represented with its 

 three areas. The middle triangular one being subcutaneous, the 

 lateral ones giving attachment to the masseter and temporal 

 muscles, (X) is the anterior extremity, which articulates with 

 the frontal bones. (A.L.) antero-lateral edge, articulates with 

 postorbital bone. (M.L.J the median lateral. fP.L.) the postero- 

 lateral. (Py. ) is the well marked process which gives attachment 

 to the parieto-maxillary muscle. (L.P.J lateral plate of the 

 parietal. (PJ the posterior extremity which articulates with the 

 supraoccipital. 



Fig. 2. — The parietal bone. The inferior surface is represented together 

 with the lateral plate. (L.P.J the lateral plate is seen to have an 

 anterior depression, which is portion of the orbital fossa ; while 

 there is also a posterior depression, which gives attachment to the 

 parieto-pterygoid and parieto-palatine muscles. (OS.) is the 

 position of the orbitosphenoid bone, helping to form the anterior 

 portion of the orbital fossa. Between the lateral plates below, 

 the basi- and parasphenoid bones fit ; while the prootic joins 

 its postero-lateral margin. (O.F.J is portion of the optic foramen. 



Fig. 3. — The frontal bone with the vertical septum of bone (V.S.) 



Fig. 4. — Postorbital bone, showing its twisted nature. To the inferior 

 portion of this bone the fascia of the venom gland is attached as a 

 special ligament. 



Fig. 5. — The basisphenoid (B.S.J and parasphenoid bones united. The 

 inferior surfaces are displayed showing the excavated parasphen- 

 oid, with a trabecula cranii on either side (T.G.J. Posteriorly 

 the prominent keel of the basisphenoid is seen, while on either 

 side of this the bone is excavated to give attachment to the spheno- 

 pterygoid muscle. (Px.J is the process which articulates with 

 the inferior surface of the basioccipital. 



Fig. 6. — The superior surface of the para- and basisphenoid bones. (S.T.J 

 the sella turcica. 



Fig. 7 — The basioccipital bone ; the inferior surface. The anterior portion 

 has an excavated area which articulates with the basisphenoid. 

 Four prominent spinous processes are seen^ which give attachment 

 to the rectus capitis anticus, and the tendon of the sacro-lumbalis 

 {S.L.) 



