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"Fig. 24. - Pterylosis of Cyoselus apus, drawn by Coues after Nitzsch; right hand upper, left hand lower, surface. 1 spinal tract; 2. humeral; 3. femoral; 4. capital; 5. alar; 6. caudal; 7. crural; 8. ventral." Elliot Coues, 1884

Pterylosis of Cypselus Apus

"Fig. 24. - Pterylosis of Cyoselus apus, drawn by Coues after Nitzsch; right hand upper, left hand lower,…

"Pterylosis of Columba livia. A, ventral; B, dorsal. al. pt, alar pteryla or wing-tract; c. pt, cephalic pteryla or head-tract; cd. pt, caudal pteryla or tail-tract; cr. pt, crural pteryla; cr. apt, cervical apterium or neck-space; fm. pt, femoral pteryla; hu. pt, humeral pteryla; lat. apt, lateral apterium; sp. pt, spinal pteryla; v. apt, ventral apterium; v. pt, ventral pteryla." -Parker, 1900

Rock Pigeon Feather Tracts

"Pterylosis of Columba livia. A, ventral; B, dorsal. al. pt, alar pteryla or wing-tract; c. pt, cephalic…