86 The Birds of Cambridgeshire 



have been found in our county about 1829, and eighteen years 

 later in Norfolk. Always a migrant the bird still continues 

 to visit our shores in spring and autumn, but is hardly likely, 

 in view of the change in the condition of the country, to 

 remain with us again during the summer. An egg, now in 

 the University Museum of Zoology, was bought in the Cam- 

 bridge market in 1847. 



14. Hydrochelidon nigra (Linn.). Black Tern. 

 This species, once a regular migrant to England for pur- 

 poses of reproduction, and by no means uncommon on many of 

 our fens and marshes, has long since ceased to breed there, 

 the last eggs having been found in Norfolk in 1858. The 

 ' Blue Darr,' or ' Car-Swallow/ as it is locally named, may 

 often be seen as late as, or even later than May, round the 

 Broads or the smaller waters of the eastern counties, but 

 no evidence of its nesting of recent years is obtainable, while 

 in Cambridgeshire it probably was never particularly common, 

 though immense flocks appeared near Bottisham in 1824, and 

 at least one nest was discovered. In 1831 flocks were seen at 

 Gamlingay. 



For further details of the above-mentioned species, or those 

 in the list below, the reader may be referred to 



Yarrell's History of British Birds, ed. iv. 



Hewitson's Coloured Illustrations of the Eggs of British 

 Birds. 



Professor Newton's Dictionary of Birds. 



Mr Howard Saunders' Illustrated Manual of British 

 Birds. 



And for the county in particular 



Jenyns' Observations on the Ornithology of Cambridgeshire, 

 in the second volume of the Transactions of the Cambridge 

 Philosophical Society. 



The Victoria History of the Counties of England. Cam- 

 bridgeshire. (Article on Birds by the present writer.) 



