. A practical handbook of British birds . 5, tarsus 26-27, bill from feathers 42-50, greatest depth35-38 (16 British breed-ing birds measured).£ wing 148-164, billlength 43-48, depth 34-38 (19 British breedingbirds). First winter <$and? wing 138-148, billlength 31 - 37, depth18-20. Primaries : 1stand 2nd about equaland longest, 3rd 3-8mm. shorter, 4th 10-16shorter, 5th 19-28shorter. Outer second-aries shorter than 10thprimary, inner onesabout equal to 9th, tipsrounded. Tail roundedand central pair shorterthan rest, 16 feathers,tips rounded. Tibia barefor a short distance nearjoint and inser
. A practical handbook of British birds . 5, tarsus 26-27, bill from feathers 42-50, greatest depth35-38 (16 British breed-ing birds measured).£ wing 148-164, billlength 43-48, depth 34-38 (19 British breedingbirds). First winter <$and? wing 138-148, billlength 31 - 37, depth18-20. Primaries : 1stand 2nd about equaland longest, 3rd 3-8mm. shorter, 4th 10-16shorter, 5th 19-28shorter. Outer second-aries shorter than 10thprimary, inner onesabout equal to 9th, tipsrounded. Tail roundedand central pair shorterthan rest, 16 feathers,tips rounded. Tibia barefor a short distance nearjoint and inserted farback ; tarsus com-pressed, three toes fullywebbed ; claws curvedand fairly sharp especi-ally inner one, middleone dilated. Bill in adultextremely compressedand expanded verti-cally, culmen arched,curving to somewhatobtuse decurved tip ;proximal half of man-dibles flattened, distalhalf with three deep,and a fourth shallower,narrow, curved groovesand c orresponding ridgescurving backwards nearly to base ; in summer at base of upper. The Southern Puffin (Fratercula arctica grabos). A. Adult,summer. B. Adult, winter. C. Juvenile. 810 A PRACTICAL HANDBOOK OF BRITISH BIRDS. mandible a narrow, raised, horny rirn with minute holes throughwhich aborted feathers grow on posterior margin ; this rim isshed with rest of outer sheath of bill in autumn making whole billmuch smaller and base of different shape ; lower outline of undermandible in summer slopes upwards gradually from base to tip, butin winter, when outer sheath is shed, has a prominent angle. Nostrila long slit near cutting edge of basal half of upper and until about one year old with comparatively shallowand small bill without grooves, culmen sloping but not arched,gonys about half length of lower mandible, angle prominent. Insecond summer bill as adult but smaller, not so arched and distalhalf with only two shallower grooves. Rosette of thick,puckered skin at gape in adult summer, reduced to narrow ba
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1920
