104 STRUCTURE AND CLASSIFICATION OF BIRDS 



Biventer Cervicis. The two muscles are perfectly separate 

 from each other. They arise tendinous from the spiuous 

 process of the first dorsal vertebra. Then follow a tendon 

 of an inch long, a belly of two inches, again a tendon of four 

 inches, then another muscular belly of one and a half inch, 

 which is inserted fleshy on to the occipital below the coin- 

 plexus. In some kingfishers (q.v.) the two muscles are 

 joined by a tendinous limb. 



Complexus. This muscle arises from the transverse pro- 

 cesses of the third and fourth cervical vertebra, and from 

 the fibres covering the inter trahsversarii of the same. It 

 is inserted, separated from its fellow by a septum, on to the 

 transverse ridge of the occipital. The muscle is entirely 

 fleslry. 



Longissimus Dorsi. It arises by a series of fleshy fibres 

 from the front edge of the ilium, becomes tendinous in the 

 middle, and then is inserted by fleshy fibres on to the lateral 

 surface of the vertebral spine next in front ; the next anterior 

 part arises tendinously from the spinous process of the most 

 posterior uncovered dorsal vertebra, and is inserted on to 

 the vertebra next in front : then follow two of precisely 

 similar relations ; the next is carried on to the dorsal surface 

 of the longissimus dorsi, as also is the last or most anterior 

 portion. 



Ilio-costalis. This complex muscle' lies laterally to the 

 foregoing muscle ; it is fused at the edge with its fibres. It 

 arises from the ilium and from the transverse process beside 

 the attachment of the rib ; two similar slips in front of this 

 arise from the transverse process and from the adjacent 

 surface of the rib. The ends of the slips are inserted partly 

 on to the surface of the ribs and partly pass on to the lateral 

 musculature of the neck. 



Cervicalis Ascendens. This is the lateral muscle anterior 

 to the ilio-costalis. It consists of five distinct slips arising 

 from the transverse processes of vertebrae xvi.-xi., with the 

 exception of xn.- The two posterior are inserted on to 

 the vertebrae next in front ; the next two are inserted on to 

 the surface of the oblique muscles next in front ; the last 



