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. Tlie dermo- tensor jmtugii. — That duplicature of 

 the common integument, of a triangular form, which is 

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

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

 as the parapatagimn, in contradistinction to the pro- 

 patagium, or the alar integumental duplicature. 



Lying within the free marginal fold of the parapatagial 



drcrmio •Le,Tn,p^raZfCs 



Fig. 1. — Eight lateral view of the skull and mandible ot Corvus corax sinuatus, 

 designed to show the origin and insei'tion of the muscles of the head, 

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



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-aspcct 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 



