BY W. J. McKAY. 947 



inserted on the exoccipital close to the insertion of the spinalis. 

 In Diemenia the muscle is very conspicuous, and is developed in 

 proportion to the slight insertion of the spinalis on the skull. 



We consider that this muscle represents the complexus, 

 although it is on the same plane as the semispinalis. 



M. TRACHELO-MASTOIDEUS. 



This muscle is formed by the continuation of the bundles of 

 the longissimus on to the skull. The muscle is a well-defined 

 band inserted on the exoccipital immediately beneath the 

 squamosal bone, being partly hidden from view by the complexus. 



M, CERVICALIS ASCENDENS. 



This muscle represents the continuation of the accessorius and 

 sacro-lumbalis on to the skull. As these muscles run toward the 

 head the bundles coalesce and form a single column of muscle, 

 which is inserted on the lower tubercle of the exocciptal, being 

 covered by the tendon of the superior rectus anticus at its 

 insertion. 



The muscle, like the spinalis, is produced on to the head to 

 serve a special function, since by its action it helps the snake to 

 *' strike," and afterwards helps to disengage the fangs by pulling 

 the head first to one side and then to the other. 



The Internal oblique stratum. 



The internal oblique stratum comprises the greatest part of the 

 muscles that go to make up the bulk of the snake's body. If we 

 reflect the anterior prolongation of the sacro-lumbalis column, we 

 come on a sheet of muscle springing from the diapophyses of the 

 anterior vertebrae, which are without ribs. The bundles com- 

 posing the sheet run backwards and outwards till they meet the 

 first rib, whereon some of the fibres are inserted, while others are 

 prolonged over the external surface to be inserted on the second 

 rib. This sheet represents the scalene group. If we follow the 



