42 PROCEEDINGS OF THE ACADEMY OF 



belong to a species that has escaped the notice of later ornitho- 

 logists.^ 



Thalasseus regius. 



This tern certainl}^ breeds somewhere in the vicinity ; for, 

 although I did not find any nests, I saw it constantly through 

 two summers, and occasionally noticed birds so young that the}"^ 

 were still receiving attentions from their parents ; while in June 

 and July small flocks were often noticed pursuing so straight a 

 course for long distances, that I had no doubt they were passing 

 directly between their nests and their feeding-places. It commonly 

 arrives from the south early in April, and through this and the 

 next month is more abundant than at other times until the fall — 

 a part, I presume, passing further north. It becomes numerous 

 again in September, and so continues until the end of November. 

 I cannot say whether or not any remain all winter, but think that, 

 if observed at that season, it will be an exceptional case. It is 

 more wary than any of the other terns, and is always the first 

 to rise among the miscellaneous troops that fleck the sand-bars. 

 It is conspicuous by its size and bright red bill ; and the young 

 are easil}' distinguished hy the smaller size, yellow instead of 

 red bill, and spotted plumage. The old birds lose the black 

 pileum in September, the crown then becoming white, bordered 

 behind by the long, loose blackish feathers of the occiput, and 

 a few other dark ones on the sides of the head. The bill in 

 winter is not so vivid in color as in summer, and much shorter. 

 All the changes of the old are finished b}' October ; but the j^oung 

 remain blotched, and with mere traces of the pearl-blue mantle, all 

 the fall. I took one old bird with the feet curiously mottled with 

 yellowish and black, and yellow claws — probably a pathological 

 state, although the bird appeared perfectly health3\ These are 

 vigorous, spirited birds, showing good fight when captured, and 

 strong enough to bite prett}' severely. Their voice is loud and 

 raucous, though still without the deep guttural intonation of that 

 of the shear-waters. 



Thalasseus acuflavidus. 



Chiefly a migrant, but also a winter resident, sparingly ; none 

 observed to pass the summer here. It becomes numerous early 

 in April, with the last, and remains through part of May ; returns 



' Qu. Larus capistratus of Bonaparte's Synopsis. 



[May 9, 



