THE DERMAL MUSCLES. 7 



larynx, which are the chief structures found immediately 

 above it. When this muscle contracts, these parts will 

 be compressed and elevated. 



6. The dermo- tensor patagii. That duplicature of 

 the common integument, of a triangular form, which is 

 found in the Raven, as in other birds, between the root 

 of the neck and the top of the shoulder, may be designated 

 as the parapatagium, in contradistinction to the pro- 

 patagium, or the alar integumental duplicature. 



Lying within the free marginal fold of the parapatagial 



FIG. 1. Right lateral view of the skull and mandible of Cornrs cor ax sinuntus, 

 designed to show the origin and insertion of the muscles of the head, 

 &c. Life-size, by the author, cc, origin of the circumconcha. 



duplicature in the Raven, we discover a well-developed 

 bundle of muscular fibres, the mesial ends of which 

 spread out, to either become, as a few of them do, 

 inserted into the skin upon the antero-aspect of the root 

 of the neck, or else pass obliquely upwards to blend with 

 the fibres of the dermo-temporalis. This muscle I 

 designate as the dermo-tensor patagii, and externally its 



