532 



API'KNDIX. 



H. The Outer Covering (Indumentum). 



142. Outer covering (Indmuenlum ; Ptilosis). The exterior of the bird in detail. 



143. Feathers (/^/iirair). Composed of ihes^ewi and the wefcs. 



144. Steva (Saiptis). The eatire central axis of the feather. 



145. Quill (Cnlamus). The hollow horny hasal portion of the feather. 



146. Shaft [liUu-liis). The solid terminal portion of the stem in nliith the fibres 



are implanted. 



147. "Webs (Pogonia). The series of fibres implanted on Ciicli side the shaft, generally 



stift', and having little 



148. Hooks or barbules along the edges, by which adjacent ones interlock ; sometimes 



soft, with the barbules not interlocking, the barbules sometimes wanting. The 



149. Inner ■web (Pogonium inunuim) is situated on the inner side of the shaft ; the 



150. Outer {externum), on the outer side. 



151. Vane ( Vexillum). The shaft and webs taken together, or the portion of llie feather 



left when tlie barrel or quill is cut away. 



