36 ANATOMY OF THE WOOD RAT 



from the cranial border of the obhquus abdominis externus, 

 extending partly superficial to the medial division of the 

 scalenus. It passes into four slender tendons which are 

 tucked in, each succeedingly deep to the preceding, and 

 inserted upon the transverse processes of the first four 

 cervical vertebrae, that to the atlas being shghtly the 

 largest. In a single specimen the portion of the origin 

 from the third rib seemed to be lacking. 



In both Neotoma and Teonoma origin is from the fourth 

 and fifth ribs only. 



M. longus colli (figs. 8, 10) lies in contact with its 

 antimere between the oesophagus and the cervical vertebrae. 

 It is a muscle complicated in its attachments, which are 

 exceedingly difficult to follow with precision. Suffice it 

 to say that the thoracic portion arises from the bodies of 

 several of the thoracic vertebrae, the insertion being for 

 the most part upon the ventral branch of the transverse 

 process of the sixth cervical vertebra, especially modified 

 in so many mammals. The cervical portion, being merely a 

 continuation of the last, arises from the transverse proc- 

 esses and centra of the cervical vertebrae, and the fibers, 

 converging cranio-mediad, are inserted upon the tubercle 

 upon the ventral arch of the atlas. In Teonoma the 

 cranial portion is larger and better defined. 



M. longus capitis (figs. 8, 23) has origin from the trans- 

 verse processes of the middle five cervical vertebrae. In- 

 sertion is upon the anterior portion of the basioccipital. 

 In Teonoma origin seems to include the seventh vertebra 

 as well. 



M. rectus capitis anterior (fig. 23) is a small muscle 

 easily overlooked. It extends from the atlas to the basioc- 

 cipital just caudad of the longus capitis. 



All muscles of this group are innervated by branches of 

 the cervical nerves, but these were not followed with 

 exactitude. 



