nasovB. 



useful sort, however — and exceedingly charming birds thej are 

 — are what Buffon styles Ooquille Hollandadse, or Dutch sheU- 

 pigeons, " because they have, at the back of their head, re- 

 versed feathers, which form a sort of shell. They are also of 

 short stature. They have the head black, the tail and the ends 

 of the wings also black, and all the rest of the body white. 

 This black-headed variety so strongly resembles the Tern 

 (hirondelh de mer), that some persons have given it that 

 name." Several other fanciful names have been bestowed 

 apon it, but none appears so appropriate as that of Nun, 

 especially in the black -headed variety. The best-marked birds 

 will sometimes throw out a few foul feathers ; from such birds, 

 however, though not so much valued in themselves, can often 

 be obtained as clean-feathered birds as those that are not. 



