MUSCLES OF THE BODY. 131 



distinguished as the Mm. rotatores; no separate layer of this 

 sort is to be made out in the cat. 



Mm. interspinales. Muscle-bundles passing from the 

 spinous process of one vertebra to that of the vertebra imme- 

 diately craniad or caudad of it. They are best developed in 

 the lumbar region. 



Mm. intertransversarii. Muscle-fibres interconnecting 

 the transverse processes. In the lumbar region the inter- 

 transversarii mediales connect the accessory and mammillary 

 processes ; the intertransversarii laterales lying between the 

 transverse processes. In other regions only one set of the 

 intertransversarii is to be distinguished. 



(<) Dorsal Muscles of the Cervical Region. The clavotra- 

 pezius (Fig. 68, d} and occipitoscapularis (Fig. 73, a) have 

 been described in connection with the muscles of the shoulder. 

 The remaining muscles of this region may be considered as 

 differentiations of the general vertebral musculature (M. ex- 

 tensor dorsi communis). 



M. splenius (Fig. 73, .) A large sheet of muscle cover- 

 ing the dorsal part of the side of the neck, beneath the trapezii. 



Origin from the whole cervical ligament and from the fascia 

 covering the deeper muscles along a line which extends from 

 the first thoracic spinous process caudolaterad for .about t\vo 

 centimeters. 



Insertion by a thin tendon into the whole lambdoidal ridge. 

 Laterad the tendon may be fused with that of the longissimus 

 capitis (Fig. 73, g). 



Relations. Outer surface with the sternomastoid (Fig. 

 68, c), occipitoscapularis (Fig. 73, a), clavotrapezius (Fig. 

 68, /), rhomboideus, tendon of the serratus posterior superior 

 (Fig. 73, /), and the levator scapulas (Fig. 73, //). Lateral edge 

 closely united with the longissimus capitis (Fig. 73, g~). Inner 

 surface with the longissimus capitis, complexus (Fig. 69, <), 

 and biventer cervicis (Fig. 69, a). 



Action. Lateral flexor of the head. The two together 

 elevate the head. 



M. longissimus capitis (trachelomastoideus) (Fig. 73, g\ 

 Fig. 69, e\ This is a slender muscle lying close against the 



