BY W. J. McKAY. 983 



Fig. s. — The bones of the upper jaw ; external surfaces. (M.) The maxilla 

 carrying three perforated fangs in front, and three solid teeth 

 behind. (Tr.) the transpalatine with the well marked process 

 (P.G.), which gives attachment to the internal pterygoid muscle. 

 (PL) the palatine carrying solid teeth. (Pt.) the pterygoid with 

 solid teeth. 



Pig. 9. — Superior surfaces of same bones. The concavo-convex joint 

 between the maxilla and transpalatine is seen ; also the exca- 

 vated internal edge of the maxilla. The surface of the ptery- 

 goid is seen which gives attachment to the parieto-pterygoid and 

 spheno-pterygoid muscles. 



Fig. 10. — Inferior surface of the same bones ; the excavated surface of the 

 pterygoid is seen which gives attachment to the internal pterygoid 

 muscle. 



Fig. 11. — The prefrontal (Pr.F.) is seen, and on its superior edge is a well 

 marked hinge-joint (H.J.), which articulates with the frontal. 

 The articulating surfaces between the prefrontal and the maxilla 

 are seen to differ from that present in most venomous snakes. 



Fig. 12.— The skull viewed from above. On the right side the postfrontal 

 and the prefrontal have both been removed. 



Fig. 13.— Muscles of the head from above. On the left side the masseter 

 has been drawn aside, and the attachment of its superficial fibres 

 to the posterior portion of the venom gland [V.G.) is shown. [M.') 

 is the deeper portion of the masseter, which chiefly goes to the 

 lower jaw. The anterior temporal (^.7\) is displayed. (Z.L.) is 

 the zygomatic ligament attached to the venom gland. (Ft.) are 

 the fibres of the platysma spreading out to be lost anteriorly. The 

 retractor quadrati is seen passing back beneath the retractor oris, 

 but above the depressor mandibulse. On the left side the spinalis 

 dorsi has been removed, and the semispinalis is seen attached to 

 the skull. 



Fig. 14. — The muscles of the head are seen from the side. The retractor 

 oris {P.O.) is reflected, and the depressor mandibulse is pulled 

 aside. The attachment of the superficial portion of the masseter 

 to the gland is seen, while the attachment of the masseter, poste- 

 rior temporal, and internal pterygoid to the lower jaw is also seen. 

 [S.L.G.) the superior labial gland. (I.L.G.) the inferior labial. 

 (F.7).) the venom duct. 

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