584 GAVIA. MEW. 



Their cries are loud, shrill, and harsh ; and they have also a 

 laughter-like cry. Much more active than the Gulls, they 

 perform their aerial evolutions with great celerity. Species 

 are found on all the maritime coasts ; hut in the cold season 

 they desert the frozen regions. They are all gregarious, 

 feeding and breeding in society, some forming their nests on 

 the sea-shore, in rocky or grassy places, others on inland 

 marshes or in islands of lakes. They are composed of dry 

 grass or sea-weeds, and generally contain three eggs, which 

 are broadly ovate, olivaceous, brown, or grey, dotted or 

 blotched with dark brown and grey. The young, at first 

 covered with parti-coloured down, leave the nest if molested, 

 and conceal themselves by squatting. The plumage, at first 

 mottled with brown, becomes lighter at the first moult, and 

 in two years or less is perfected. The prevailing colours are 

 white and light greyish-blue, with black on the wings. In 

 winter the head is light-coloured ; but in summer generally 

 deep grey, brown, or black. 



This genus is directly connected with Larus on the one 

 hand, and with Sterna on the other. Several of the species, 

 the Fork-tailed at least, have been generically named Xema ; 

 but as that name appears to be mere " nonsense," it having 

 no etymology, it ought to be treated as such. The genus 

 itself so called is not the genus above defined, most of the 

 species of which are included in Brisson's genus Gavia, 

 which name I therefore adopt, though it also is not classical. 



