526 APPENDIX. 



above the other, and always destitute of teeth. The anterior pair of hmbs is 

 developed into wings which, however, are not always capable of use in flight ; 

 the posterior serve as legs for the support of tlie liody in an oblique or nearly 

 erect position. Tlie body is covered with fcathei-s of variable structure and charac- 

 ter, both in the young bird and the old. (Tlic wings are apparently wanting in 

 some fossil species.) 



The following terras, English and Latin, ;u-e those most general!}- employed in 

 describing the cxteraal form of birds, and are jirincipally as defined by Illiger. 

 In cases where there is no suitable Englisli word in use, the Latin ccjuivalcnt only 

 is given. The figure selected for illustration, drawn by Mr. 1!. llidgway, is that 

 of the common American robin (Turdus migratorius, L.), and will be familiar to 

 most students of ornithology. 



A. Body in General (Corpus). 



1. Feathers {Plnma). A dry clastic oliject, with a central stem at one end forminjj a liol- 



low horny tube implanted in the skin at its tip, the other i'catheicd on opposite sides. 



2. Quills {Pemia). The large stitF feathers implanted in the posterior edge of the win^ and 



in the tail. 



3. Plumage {Plilosis). The general feathery covering of the body. 



4. Unfeathered {Implumts). A portion of skin in which no feathers are inserted. 



5. Upper parts {Xolaum). The entire upper surface of the animal. (Sometimes restricted 



to the trunk.) 



6. Lovrer parts ( Gos^cffum). The entire lower surface of the animal. (Sometimes restricted 



to the trunk.) 



7. Anterior portion {SteJhimim). Tlie forward part of the body (about half), both upper 



and under surfaces, including tlie chest. 



8. Posterior portion [Urmim]. The hinder portion of the body (about half), including the 



abdominal cavity. 



B. The Head (Cajmt). 



9. Bill {Rostrum). The projecting jaws, one above the other, united by a hinge joint behind, 



and lovored bv a horny sheath, or a skin, and enclosing the mouth. 



10. Maxilla, or upper jaw {Manila]. 



11. Mandible, or lower jaw {Manflibida). 



12. Ramphotheca. The horny covering, or sheath of the jaws. 



13. Rhiuotheca. The covering of the upper jaw. 



14. Gnathotheca. The covering of the lower jaw. 



15. Cere {Cera, or Ciroma). A skin at the base of the maxilla, in certain birds. 



(In birds without a horny sheath to the bill, the cere may be considered as 

 extending to its very tip.) 

 IG. Edges of bill {Tomia). The margins of upper and lower jaws where they come in 



contact. We have thus a 



17. Maxillary tomium, and a 



18. Mandibular tomium. 



19. Gape or Commissure {Commissurn). The junction of the tomia, or of the two hills. 



