600 GAVIA RIDIBUNDA. 



resembling the sounds of laughter ; J^arus argentatus has a 

 louder chuckling cry, perhaps still more resembling laughter ; 

 Larus marinus, a strong, clear, loud barking or yelping note. 

 The young of Larus ridibundus emit a shrill scream ; those 

 of Larus canus an undulated scream ; and those of Larus 

 argentatus a continuous louder scream. 



The Guillemots, which were very numerous, but kept 

 chiefly in the open part of the firth, sometimes rose as the 

 vessel approached them, and ran, as it Avere, along the sur- 

 face in a straight line, flapping their -vvings all the while, to 

 the distance of a hundred yards or more, although most of 

 them dived when Ave came near them. The Red- throated 

 Divers, which, although similar in colour to the Guillemots, 

 Avere easily distinguished by their superior size and the com- 

 paratively greater length of their necks, also frequently rose 

 and splashed along to the distance of from tAvo to four 

 hundred paces. Although they fly Avith great speed when 

 fairly on Aving, they are heavy birds, and, in removing to a 

 short distance, apparently do not think it necessary to rise 

 into the air, as a Gull or Tern Avould do, but shoot out in a 

 straight line, striking the water Avith their Avings and feet, 

 the latter, in particular, throAving it to a distance behind. 



Above Charleston, the Gulls and Divers disappeared 

 from the open Avater, and the flocks of the former seen along 

 the bays Avere not more numerous than they would be in 

 ordinary cases. At Bo'ness, on the southern side of the firth, 

 not a single bird of any description Avas to be seen. Near 

 Alloa, hoAvever, I observed a flock of Larus fuscus composed 

 of thirty-eight individuals, and farther up many birds of the 

 same species, Avith a few of Larus canus, Larus argentatus, 

 and Larus ridibundus, Avere seen here and there, little bands 

 of them floating in the bays. In the narroAV part of the 

 estuary, of Avliich the flat margins are secured by Ioav em- 

 bankments, and sometimes fringed Avith very tall reeds, 

 Arundo phragmites, a Heron, Ardea cinerea, a flock of 

 Knots, Tringa cinerea, several Mallards, Anas Boschas, and 

 three Red-breasted Mergansers, Mergus 8errator, Avere ob- 

 served. 



On the Avhole, fcAV sights could be much more interesting 



