RARER BIRDS OF MASSACHUSETTS. 643 



year Mr. Maynard succeeded in obtaining the young of S. 

 macroura at Ipswich, when they were just able to leave 

 the nest. A comparison of these with the young of 8. 

 hirundo of corresponding age, or even with mature 8. hi- 

 rundo, leaves no question as to their distinctness. The dif- 

 ferences between the young of the two are as great as 

 between the adult. In these nestlings of 8. macroura the 

 color of the rump is as different from that of the back as it 

 is in the adult, the plumbeous bluish mantle not being con- 

 tinued to the tail as in 8. hirundo. 



The distinctive differences then between them may be 

 stated thus : 



8. macroura has the under parts strongly tinged with 

 plumbeous, with the throat and under tail coverts abruptly 

 white, while in 8. hirundo the under parts are faintly washed 

 with plumbeous which fades gradually into white on the 

 throat and under tail coverts. 8. macroura has the shorter 

 tarsi, and the shorter, smaller and more delicately shaped 

 bill ; in color the bill of the latter is uniformly carmine, not 

 coral red with a black tip, as in the other, and the tarsi and 

 feet deep vermilion, almost lake (not light vermilion as in 

 8. hirundo), and roughened. The rump is abruptly white at 

 all ages, while in 8. hirundo it is dilute plumbeous, shading 

 gradually into the color of the back. In size and general 

 proportions there are no essential differences between them. 



So long as the young of 8. macroura was unknown, it 

 seemed that the differences in color between the young of 

 8. hirundo and the adult of that species, if carried a little 

 further, would result in a form, so far as co\or is concerned, 

 exactly like 8. macroura.* 



ROSEATE TERN. 8terna paradisea Briinn. Occurs plen- 

 tifully on Muskeget Island during the breeding season. Was 

 also taken by Mr. Maynard and myself at Ipswich in June, 



* For an excellent revision of the Terns of North America, see Dr. Elliott Cones' 

 paper on this subject in the Proceedings of the Philadelphia Academy of Natural Sci- 

 ences, 18(52, p. 535. 



