MYOLOGY OF REPTILES. 



233 



(liapopliysis of the atlas : the tendon so inserted is shown at 33, 

 fig. 148. 



The comjih-xus, fig. 148, 23, arises from tlie diapophyscs of the 

 first tliree cervicals, and is inserted into the paroccipital : in 

 fig. 150, the hindmost origin of tins mnscle is marked 25. 



The rectus capitis anticus lonfjus, fig. 148, 29, arises from the 

 hypapophyses of the third and second cervicals, and is inserted 

 into the side of the basioccipital. The rectus capitis anticus 

 hrevis, fig. 152, 30, arises from the atlantal hypapophysis, and is 

 inserted into the basioccipital. The rectus cajritis piosticus major, 

 fig. 148, 31, arises from the neural spines of the axis and atlas, 

 and is inserted into the paroccii)ital. The rectus capitis posticus 

 vimor, ib. 31, arises from the neural arch and diapophysis of 

 the atlas, and is inserted into the base of the exoccipital. 



The largest and most remarkable portions of muscular segments 

 of the trunk are those which are combined to effect the retraction 

 beneath the carapace of the head and neck. The retralwiis 



149 



Siilo A'k'w (if Uirjik-iiiupcles aii'l ilcciicr .sc;Ued linib-iiuisclcf?, ICtivjs Hni-oprra. xxx^'iii. 



capitis collique, figs. 149, 150, 27, arises by six fleshy fasciculi 

 from the neural arches and spines of the eighth to the fifth 

 dorsals inclusive ; these pass forward, blending together, and then 

 detach four tendinous insertions : of these, the anterior and 

 longest, as well as strongest, is into the basioccipital fossa ; the 

 other three are into the diapopliyses of the fourth, fifth, and sixth 

 cervicals. It is not difficult to sever the part of the great re- 

 tractor connected with the cervical insertions, as a distinct muscle 

 from that inserted into the occiput. The hiventer cervicis, figs. 

 150, 151, 2-i, arises from the neural spines of the fifth, fourth, and 



