PRELIMINARY LIST OF THE MAMMALS OF NEW YORK. 325 



Helme I visited Great Gull Island for the purpose of learning the con- 

 dition of the colony of meadow mice that formerly existed there. 

 Careful search on every part of the island for signs or runways of the 

 mice failed to reveal any indication whatever of their presence. The 

 natural conclusion is that the race has been nearly if not quite exter- 

 minated. The cause is not difficult to see. Within the past year the 

 island, which contains only about 15 acres, has been occupied by the 

 United States government as a coast defence station, and the construc- 

 tion of forts at each end of the island has necessitated disturbances of 

 the soil and change in the topography of practically the whole surface. 

 The forts themselves with the shanties erected for the use of the laborers 

 cover a considerable portion of the island, hills have been levelled, the 

 little fresh water swamp has been filled in, and the whole surface twice 

 burned over. The destruction of all the rubbish and dead vegetation 

 deprived the mice of any cover where they could seek shelter, and the 

 sparseness of the new growth made it easy for us to examine every 

 available hiding place. Doubtless any of the mice which may have 

 escaped the fires were captured by the cats which roam at will over the 

 island. 



" On the same day we visited Plum island, situated between Great Gull 

 Island and the eastern end of Long Island. Here we found Microtus 

 quite abundant about the edges of the swamps on the western end of the 

 island, and a series of 14 was secured. Comparison of these specimens 

 with the mainland form shows that the Plum island mouse is like the 

 latter and entirely different from Microtus nesophihis" 



Principal records. The first published record of this mouse is contained 

 in a paper by Dr Basil Hicks Dutcher on the birds of Little Gull Island 

 ('89). Dr Dutcher says, " Great Gull Island was purchased by the 

 Government to serve as a garden for the keepers of the Little Gull Light, 

 but it was so overrun with mice that it was useless for the purpose. . 

 I secured one specimen of the resident mouse, which proved to be 

 a juvenile Arvicola riparius." This specimen afterward became Mr 

 Bailey's type of Microtus insularis. Mr J. Harris Reed has recently 

 described in considerable detail the fortifications on Great Gull Island 

 and their effect on the fauna of the place ('98, p. 41-43). 



Mr Frank M. Chapman informs me that he visited Great Gull 

 Island during the summer of 1889. He found the mouse colony in 

 the same flourishing condition described by Dr Dutcher. Seven speci- 

 mens which he collected are now in the American museum of natural 

 history. 



