Compressed - refers to the shape of a part when viewed in cross-section 

 (see Fig. 7). Laterally compressed means the sides are flat, as 

 in an oystercatcher's or puffin's bill or a loon's tarsus: 

 (see loon foot illustration). 



Dorso- ventral ly compressed means the top and bottom are flattened 

 as in a duck's bill . 



Figure 1. Cross-sectional shapes of tody parts, in this case 

 bills. 



COMPRESSfp V (PoFFIN BILL) 



DORSO- 



CoMPHESSEp 



(DUCK BILL) 



Contour feathers - those that cover the bird's body parts other than 

 feathers of the wings and tail and down feathers. 



Culmen - the uppermost ridge of the bill running from the bill's tip to 

 where it meets the skin or feathers of the forehead. The culmen 

 is thus a specific part of the upper bill (see Fig. 9). 



Figure 9- Several parts of a bird's bill; see also Figure 5. 



NARIS 



or GONYS 



