Pterylosis of Cypselus Apus Small 320×160 Medium 640×319 Large 1024×511 Download TIFF Original 2400×1197 | (323.3 KB) Description "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 Keywords alar, bird anatomy, birds, capital, Caudal, Crural, Cyoselus apus, external bird parts, feather structures, feathers, femoral, humeral, ornithology, pterylosis, spinal tract, ventral Galleries Bird Anatomy Source: Elliot Coues Key to North American Birds (Boston, MA: Estes and Lauriat, 1884)
