MUSCULAR SYSTEM OF THE RED HOWLING MONKEY 43 



Nerve supt.ly of the oblique system. — Dorsal branches of the 

 corresponding segmental nerves innervate the muscles of this system. 



Short System 



M. obliquus capitis superior: Origin is by a mixture of fleshy and 

 tendinous fibers, the last being more superficial than the former, 

 from the lateral third of the occiput just medial to the postmastoid 

 crest and below the insertion of m. semispinalis and spinalis capitis 

 (fig. 5). The belly narrows down caudally and inserts by short tendi- 

 nous fascicles on the tip of the atlantal transverse process (fig. 15). 



M. obliquus capitis inferior (fig. 15). This is a stouter muscle 

 with a broad fleshy origin from the lamina and lateral surface of 

 the strikingly developed spinous process of C 2. It passes laterally 

 toward the tip of the transverse process of the atlas, where it is 

 inserted. 



M. rectus capitis posterior major: A flat triangular muscle arising 

 fleshily from the intermediate third of the occipital squama, between 

 the insertion of the combined semispinalis and spinalis capitis above, 

 and the large retrocondylar fossa below (fig. 5). The muscle tapers 

 toward its insertion on the cranial margin of the axial spinous process 

 (fig. 15). There is a triangular space between the medial borders of 

 the major recti of each side through which the medial halves of the 

 underlying minor recti can be seen. 



M. rectus capitis posterior minor: With a shape similar to that of 

 the major, it is shorter, less strong and arises from the medial third 

 of the occiput, between the attachment of m. spinalis capitis above 

 and the rim of the foramen magnum below (fig. 5). Its fibers run 

 distad partially covered by the major to insert close to the midline 

 on the cranial border of the posterior arch of the atlas (fig. 15). 



Mm. intertransversarii laterales et mediates: In the neck fleshy 

 fibers arise from the caudal surface of a transverse process and de- 

 scend toward that of the vertebra next below. Most of the time they 

 do not show the typical paired condition, only the posterior member 

 being present and inserted m the posterior tvibercle. There invariably 

 are strong anterior and posterior muscles between C 1 and 2. The 

 spinal nerve runs in front of, or between the two muscles in the 

 few cases when the pair is complete. In the thoracic region they 

 are increasingly less developed and can be found only up to about 

 the interval T 7 to T 8. A typical lumbar intertransverse arises at 

 a metapophysis. Its bundles reach the anapophysis of the next craniad 

 vertebra and the medially adjacent capsule of the interarticular joint. 

 There are fleshy columns joining the articular processes of the proxi- 

 mal caudal vertebrae and also the tubercles of the intermediate sacral 

 crest. 



275-199 O - 



