A Monograph of Marcus Island. 103 



Honorable Walter Rothschild's plate in Avifauna of Laysan agrees 

 in color with Laysan birds before me, and, I fancy, was delineated 

 from a bird secured oh that island. Both the above plates and 

 descriptions are at variance with one another, and the Marcus 

 Island bird sufficiently to warrant the recognition of the western 

 form under a new name. 



I regret not having a specimen in our collec5lion of the species 

 recently described by my friends Messrs. Heller and Snodgrass 

 from the Galapagos under the name of Micranous diavicsus. They 

 remark that the Galapagos form differs from an Oahu bird sent 

 them from this Museum "in being darker on the shoulders, on the 

 lower parts and sides of the neck and on the sides of the head, and 

 in having a longer and stouter bill and longer middle toe." 



A perusal of the following table of measurements made up from 

 adult males taken in the same season, but seledled at random from 

 the Museum series, shows marcnsi to be a trifle the larger bird of the 

 two species; also that the Midway specimens are intermediate in size. 



I have had much pleasure in making a very careful compari- 

 son of the Marcus specimens with the thirty-four examples of this 

 genus already in the Museum, with the result given above. In 

 arriving at this conclusion I have resorted to chara(5ters taken from 

 my notes on freshly killed birds, on Oahu, Midway and Marcus 

 Islands. One of the unfortunate conditions imposed by Lieutenant 

 Akinote was that we would not be allowed to land and use fire- 

 arms. As a result the .status of Jl/. marcnsi rests on the three speci- 

 mens, two adults and one half -fledged young, which I was able to 

 secure — one from an old Japanese, one fledgling from the nest, and 

 one ( the parent of the 3'oung bird taken) was obtained by me through 

 my exertions with a bambu pole. The species was not abundant 

 in the first place, in addition to which they were quite wary, else 

 my series would have been more complete, for the orange-colored 

 feet of this black tern attracted 1113- attention at once. 



At the time of my visit the nesting season was well over, many 

 ne.sts unmistakably of this species having been deserted by the 



