U. troile

from The Collaborative International Dictionary of English v.0.48

Guillemot \Guil"le*mot`\, n. [F.] (Zool.)
   One of several northern sea birds, allied to the auks. They
   have short legs, placed far back, and are expert divers and
   swimmers.
   [1913 Webster]

   Note: The common guillemots, or murres, belong to the genus
         {Uria} (as {U. troile}); the black or foolish guillemot
         ({Cepphus grylle}, formerly {Uria grylle}), is called
         also {sea pigeon} and {eligny}. See {Murre}.
         [1913 Webster]