?l6 Mack ay on Somatcria dresseri. [October 



numbers in the shoal waters adjacent to the Islands of Nantucket, 

 Muskeget and Martha's Vineyard, where they pass the winter 

 months, and it is the only one of the Eider group which has 

 come under my immediate notice. Resembling somewhat the 

 Pacific Eider, and also S. mollissima, they are easily distinguish- 

 able from the former by their size, being much smaller, and by 

 their having the forehead much more prominent ; it is elongated 

 and depressed in the other two varieties. S. dresseri also has 

 the frontal fleshy portion of the bill much wider and more 

 prominent than in mollissima. 



Their favorite ground on this coast is about those low-lying, par- 

 tially submerged rocks which abound with their favorite food, 

 mussels {Modiola modiolus) , which are from one to four miles from 

 the mainland. Here they find the black mussel which adheres to 

 the sunken rocks, as also sea urchins. When living near some fav- 

 orite rock, they always fly out to sea after their evening meal to 

 roost, and on their return the following morning, if we take the 

 rock as a centre, they come from points covering some sixty-five 

 degrees, thus showing a remarkable dispersion during the night, 

 for they leave the rock at night in one body ; and it is curious that 

 no matter from what point they start at daybreak, or before it, they 

 are always pointed undeviatingly for the rock. In flying they 

 have a habit of carrying the head very low, on which account 

 it is easy to under-shoot them. They are most observing, and 

 notice the least thing unusual on or about the rocks or with the 

 decoys, which must be set so as to ride very steadily, and too 

 much care cannot be exercised if a successful issue is to be ex- 

 pected. 



They are expert divers, and if wounded are most difficult to 

 capture ; in fact I know of no birds more so, unless it may be the 

 Loons. They swim deeply and steadily when at ease, and are 

 rather slow and heavy in their movements, but withal graceful ; 

 but if frightened they are very agile, and if under water at such a 

 time will always come out flying separately, no two being to- 

 o-ether. They dive for the mussels outside of the breaker which 

 usually lies just outside the main rock, swimming underneath the 

 surf and pulling oft' the mussel, returning to the surface again 

 outside the breaker, but never coming up in it ; and when a flock 

 has been feeding rfn examination of the ledge, or rocks, reveals 

 the white threads, like the mycelium of the mushroom, adhering 



