56 



THE MYOLOGY OF THE RAVEN. 



Mammalia, the function of this muscle is to raise the 

 superior eye-lid. 



39. TJie depressor palpebrce inferioris, as has already 

 been stated, is easily found. Its fibres are attached 

 along the lower margin of the interorbital vacuity. 

 From this line (Fig. 22) they pass outwards beneath the 

 eyeball, to become inserted into the lower lid, where they 





t.t. 



FIG. 22. Right lateral aspect of skull of Raven, to show exact origins of the 

 principal muscles of the eye, and the tensor tympani. Life-size, by 

 the author. Lettering as in Fig. 20, with t.t., tensor tympani ; o.p. , 

 orbicularis palpebrarum ; /, lacrymal bone; I. pal. sup. , levator pal 

 pebrse superioris ; d. pal. inf., depressor pal pebrse inferioris; r.inj., 

 rectus inferior. 



antagonize to a certain extent the orbicularis palpe- 

 brarum, as by their contraction this integumental veil to 

 the organ of sight, the lower lid, is withdrawn. Owen 

 tells us that this muscle is also found in the Crocodile, 

 and I dare say in other Sauropsida. In the Raven it- 

 is the only lid of the three which is reinforced by a 



