36 Mackay, Terns of Muskeget Island. [^^""^ 



variation in color, size, shape and markings of the eggs, and I 

 failed to detect any constant feature whereby they could be 

 invariably distinguished. 



I visited Muskeget again on July 3, and with a friend walked over 

 the same ground that I did on June 20. I found about eighty- 

 five per cent, of all the eggs hatched, and the chicks running 

 about everywhere. I took from the mouth of a chick, from which 

 it was protruding, a pipe fish {Siphonostoma fuscurn)^ four inches 

 long. The bird was still too young to leave the nest. They also 

 eat a kind of sea-worm, round in shape and of irregular diameter, 

 and about four inches in length, resembling an earth-worm. 

 I regret that the only specimen which I saved was destroyed 

 before indentification. It was probably " one of the Sipunculoids, 

 Phascolosoma sp. ? " The old birds remain until incubation is 

 over and the young are able to fly and care for themselves, when 

 some of them leave, others remain in these waters until the 

 middle of October. On October 9, 1893, large numbers were 

 observed resting on the water in detached groups of a dozen to 

 thirty or forty birds, extending from Tuckernuck Shoals to East 

 Chop, Martha's Vineyard. On the i6th the same thing was 

 again noted. They were probably preparing to migrate. At 

 such times they collect on the sand bars and points until a large 

 number are together, when they all rise and continue to circle, 

 going higher and higher until lost to view. 



I have heard of but two instances of these Terns being captured 

 here during the winter; namely, on February 20, 1891, Mr. 

 Vinal N. Edwards shot a Wilson's Tern in immature plumage, in 

 Woods Hole harbor, Mass., the only one seen at the time. Again 

 at the same place on January 17, 1894, he shot another, which 

 had been frequenting the harbor for about a week previous. 

 The skin of this bird is now in the U. S. Fish Commission 

 collection. Woods Hole, Mass. ; that of the former I think is in 

 the Smithsonian collection, Washington. They are not often seen 

 resting on the water, prefering to rest on their breeding ground on 

 the upland or on the sand beaches and bars, or occasionally on 



' I am indebted to Mr. Samuel Henshavv of the Boston Society of Natural 

 History for the indentification. 



