296 



MR. R. H. BURNE ON THE 



[Apr. 18, 



One muscle in the neck-region I have not been able to 

 satisfactorily identify : — 



(Text-fig. 55. 29 a.) Origin : from the ventral surface of the 

 last cervical and first dorso-lumbar vertebrae. Insertion : upon^the 

 ventral and lateral surfaces of vertebrae iv., v., vi., vii. 



This muscle, the front end of which lies lateral to the longus 

 colli, can be separated with difficulty into at least three more or 

 less separate bellies. 



Vestigial Bach- Muscles. (Text-fig. 56.) 



The dorsal surface of the dorso-lumbar region of the vertebral 

 column is covered by a layer of intermingled muscular and 

 tendinous tissues that represents the back-muscles in a degenerate 

 condition. 



Text-fiff. 56. 



Dermochelys coriacea, anterior part of the vestigial muscles of tlie back. 



In this mass three parts can be distinguished by their position^ 

 although they ai-e in no other way separable from one another : — 



a. Fibres running from spine to spine. These parts are con- 

 tiguous in the mid-line, except where they are interrupted 

 by the neural spines. 



h. Fibres that run beside the neui^al arches above the necks of 

 the ribs. 



c. Fibres running from lib to rib. 



In f I'ont of the second pair of ribs these parts can be to a 

 certain extent separated mechanically. 



In the anterior thoracic region parts h and c are strongly 



