526 APPENDIX. 



above tho other, and always destitute of teeth. The anterior pair of limbs is 

 developed into win^s wliich, however, are not always ctipal.lo of use in flight ; 

 tho posterior servo as legs for tho support of the body in an oblique or nearly 

 erect position. The body is covered witii feathers of variable structure and clmrac- 

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

 some fossil species.) 



The following terms, English and Latin, arc those most geuernlly cm].Ioyed in 

 describing the external form of birds, and are ])rincipally as defined by flligor. 

 In cases where there is no suitable English word in use, the Latin equivalent vn\y 

 is given. Tho figure selected for illustration, drawn by Mr. iJ. Ridgway, is that 

 of tho common American robin {Turdtts mifjratorius, L.), and will be familiar to 

 most students of ornitliology. 



A. Body in Oeneral {Corpus). 



1. Feathers {Phmrr). A dry elastic olycct, witli a ccntrnl stem nt one end forming n liol- 



low horny tube implanted in the Mn nt its tip, tlio otlier feutlicrcd on op|)ositc sides. 



2. Quills (Pcmur). Thu large stiff feathers implanted in the posterior edge of the winj; and 



in the tail. 



3. Plumage {Plihsls). The general feathery rovcring of the body. 



4. XTnfeathered {Implumis). A portion of skin in whieh no feathers arc inserted. 



5. Upper parts {Xotimm). The entire upper surfaec of the animal. (Sometimes restrietcd 



to the trnnk.) 



6. Lower parts ( aastrmim). The entire lower surface of the animal. (Sometimes restricted 



to the trnnk.) 



7. Anterior portion (Steiliia-iim). The forward part of tho body (about half), both upper 



and under surfaces, including the chest. 



8. Posterior portion {UrcEum). Tho hinder portion of ilic body (about half), including the 



abdominal cavity, 



B. The Head (Caput). 



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



and covered by a horny sheath, or a skin, and enclosing the mouth. 



10. Maxilla, or upper jaw {ifarilh). 



11. Mandible, or lower jaw (^famlibula). 



18. Bampbotheca. The homy covering, or sheath of the jaws. '' 



13« Rhinoth*. ;a. The covering of the upper jaw. 



•4. Onathotheca. The covering of the lower jaw. 



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



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

 extending to its very tip.) 



16. Edges of bill (TomiVi). The margins of upper and lower jaws whore they come in 



contact. We have thus a 



17. Maxillary tomium, and a 



18. Mandibular tomium. 



19. Oape or Commissure {Commissum). The junction of the tomia, or of the two bills. 



