THE BRITISH BIRD BOOK 



xv 



35. Tarso-metatarsus, or shortly metatarsus, formed by the 



fusion of the five lower or distal tarsals (ankle bones) 

 and the three middle metatarsals (instep); called 

 "shank" in error. The back of the tarsus is called 

 the planta (sole). The bird walks on its toes only. 



36. Acrotarsium (Gr. akros, uppermost ; tarsos, foot be- 



tween toes and heel), the front of the metatarsus. 



37. Acropodium (Gr. akros, uppermost ; pous, a foot), the 



front of the toes. The under parts of the toes are 

 the pads. The first toe is known as the hallux. 



As in Fig. 1. 



FIG. 2. 



FIG. 3. 



Cere (L. cera, wax), wax-like skin which covers the base 

 of the upper mandible in some species, e.g. hawks and 

 eagles. 



Tooth, not to be confused with the tooth in the ordinary 

 sense. No existing birds have teeth. 



9. As in Fig. 1. 



FIG. 4. 



Nail or hook (dertrum). 



Lamellae, tooth-like serrations, developed especially in 



ducks and geese, and used for sifting when feeding. 



Adj. lamella ted. 



FIG. 5. 



As in Fig. 1. It shows the under wing coverts (Lesser 

 27a ; Median, 28a, etc.), the axillaries (L. axilla, arm- 

 pit), and the vent (crissum). 



FIG. 6. 



1. Pupil. 2. Iris ; pi. irides. 3. Eyelid. 



4a. Anterior canthus. ip. Posterior canthus. 



FIG. 7. 



1. Barrel (L. calamus, reed), which is hollow and trans- 



parent. 



2. Shaft (L. rhachis), filled with pithy matter. The term 



quill, which has no connection with the Latin cala- 

 mus, is rightly applied to the barrel and shaft taken 

 together. 



3. Outer web or vane (L. vexilla). 4. Inner web or vane. 

 5. Emarginate, having the margin broken by a notch. 



ALPHABETICAL LIST OP THE TERMS ILLUSTRATED BY THE FIGURES, 



WITH ADDITIONS 



Abdomen (belly), 1. 26. 



Acropodium, 1. 37. 



Acrotarsum, 1. 36. 



Aftershaft (hyporhachis), a supplementary and, as a 



rule, relatively small feather attached to the inner 



and lower surface of the main shaft. 

 Ala spuria (bastard wing), 1. 33. 

 Alar bar, a bar (white, black, etc.) across the wing (L. 



ala). 

 Albinism, a bird with plumage abnormally white. Cf. 



Melanism. 



Alula (bastard wing), 1. 33. 

 Apex, the distal end of a feather, beak, toe ; adj. apical. 



Cf. Distal. 



Auricula, auriculars (ear coverts), 1. 12. 

 Axillaries, 5. 

 Back, 1. 15. 

 Barrel, 7. 1. 



Base, the root or proximal part ; adj. basal. 

 Bastard wing, 1. 33. 

 Belly, 1. 26. 

 Breast, 1. 24. 

 Brood (A.S. brid, that which is hatched or produced 



by means of warmth ; a young bird), the nestlings 



collectively ; to brood, cover the young with the wings. 



Cf. Incubate. 

 Calamus (barrel), 7. 1. 

 Canthus, 6. 4a, 4p. 

 Cera, cere, 3. 

 Cervix (hind-neck), 1. 14. 

 Cheek, 1. 13. 

 Chin, 1. 21. 



Commissure, line of junction between the two mandibles. 

 Compressed, pressed together from the sides or laterally. 



Cf. Depressed. 



Contour feathers (penruc, plunue), all which are extern- 

 ally visible, and so determine the contour of the body. 

 They include the wing and tail quills. Cf. Down 

 feathers, Filo-plumes. 



Coverts, 1. 18, 19, 27-30 ; 5. 



Crissum (vent), 5. 



Crown, 1. 11. 



Cubitals, cubitus (secondaries), 1. 31. 



Culmen (ridge), 1. 3. 



Cuneate, wedge-shaped. 



Cutting edge, 1. 4. 



Occurred, curved downwards. 



Depressed, pressed down vertically. Cf. Compressed. 



Dertrum (nail or hook), 4. 



Distal, the end distant from the centre or axis of the 

 body; e.g. the tip of the beak is its distal end. Cf. 

 Apex. 



Dorsal, dorsum (back), 1. 15. 



Down feathers (plumule), soft feathers hidden below the 

 contour feathers, except when the latter are absent as 

 on the neck of certain Vultures where the downfeathers 

 form a ruff. In nestling birds the Downs may be of 

 two kinds: the pre-pennee, which are replaced by 

 contour feathers, and the pre-plumulae, replaced by 

 adult down feathers. 



Emarginate, 7. 5. 



Family, division of an Order. 1 



Fibula, 1. 34. 



Filo-plumes (filo-plumw), hair-like feathers, with the 

 remnant of a vane at the tip, which cluster round the 

 bases of the contour feathers. The stiff " bristles " 

 (Figs. 1. 8) are contour feathers that have entirely lost 

 their vanes. 



Flanges of gape, 1. 9. 



Flanks, 1. 25. 



1 EXAMPLE : the raven (Corvus corax) is a species of the genus Corvus, which is a division of the Family Corridee or Crows, 

 which in turn ia a division of the Order Passeres of the Class Aves or Birds. Triple terms, e.g. Corvus corax corax, Corvus 

 corax varius, Corvus corar hispanus, etc., are used to distinguish sub-species or local races. 



