History of British animals - University of Guam Marine Laboratory

116 BIRDS. PALMIPIDES.PALMIPIDES.WATER BIRDS.I. Hind toe united with the front toes by a continuous membrane. Nasalopenings indistinct.Phalacrocorax.Sula.Hind toe separate.II.a.Margin of the mandibles with corneous teeth ; the sides of the tonguewith tufts of pectinated bristles.cc.b. Bill broad. Teeth in the form of transverse plates.c. Trachea of the male with a capsular enlargement at the bronchialextremity.d. Hind toe bordered with a membrane^e. Base of the bill enlarged.Oidemia.Somateria.ee. Base of the bill plain.Clangula.Nyroca.dd. Hind toe not bordered by a membrane.e. Bill wide at the extremity.Tadorna.ee.Spathulea.Bill nearly of equal breadth throughout.Anas.Trachea of the male simple at the bronchial extremity.Cygnus.Anser.bb. Bill narrow ; margins with reflected teeth ; the upper mandiblehooked at the end.Mergus.aa. Margin of the bill and tongue destitute of teeth or bristles.short. BrachypterjE.b.Wingsc. Bill compressed and obliquely furrowed. Tridactyle.Alca.Fratercula.cc. Bill conical, subcompressed, and destitute of furrows.d. Webs scalloped. A hind toe with a broad web.Podiceps.dd. Web entire.e. Tridactyle.Colymbus.ee.Tetradactyle./. Upper mandible notched at the point.Una.ff.Upper mandible plain.Cephus.Mergulus.