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THE AMERICAN NATURALIST [Vol. LIII 



THE EFFECTS OF THE WINTER OF 1917-1918 ON THE 

 OCCUERENCE OF SAGARTIA LUCI^ VERRILL^ 



In June, 1902, I published in the American Naturalist some 

 notes on the dispersal of Sagartia lucice that tended to show 

 that this sea-anemone had spread from the neighborhood of 

 New Haven, Conn., along the New England coast as far north 

 as Salem, Mass. This migration was accomplished in approxi- 

 mately a decade, from 1892 to 1901. Since 1902 repeated ef- 

 forts have been made to discover evidences of this species farther 

 to the north than Salem but without avail. Apparently the 

 species had reached its northernmost limits. 



Sagartia lucice was first noticed in Woods Hole, Mass., in 

 1898. From that year until the present it has been an extremely 

 abundant species on the stones, mussels and eel grass in the 

 waters of this region. On Pine Island, a narrow ridge of rocky 

 gravel overtopped with coarse vegetation and lying in the swift 

 tidal currents of the Hole, the narrow beaches between tides 

 have been covered with thousands of this species of sea-anemone. 

 When this locality was visited in June, 1918, not a single speci- 

 men of Sagartia lucice could be found, though the particular 

 area examined had been covered with many individuals the 

 year before. Nor was this condition due to the relatively early 

 date at which the search was made. Repeated attempts during 

 low tides in July and August never yielded at Pine Island 

 more than two or three specimens at a time, and it was quite 

 clear that Sagartia lucice, once so prevalent in that locality, had 

 suddenly become all but extinct there. The same was true of 

 other situations in and about Woods Hole. In fact, a general 

 search showed that in not a single location where this sea- 

 anemone had been abundant in 1917 could there be found more 

 than a paltry number of specimens in 1918. 



The occasion of this sudden and great diminution in the num- 

 bers of Sagartia lucice is to be attributed, I believe, to the rigor 

 of the winter of 1917-1918. The cold and ice of this winter 

 were almost unprecedented. Mr. Vinal Edwards, the veteran 

 collector of the laboratory of the United States Bureau of Fish- 

 eries at Woods Hole, has kept a continuous record of the weather 

 conditions of this region for a long period and this record 

 shows, as might be expected, that the winter conditions in 1917- 

 1918 were more severe than for many years past. In no win- 

 1 Contributions from the Zoological Laboratory of the Museum of Com- 

 parative Zoology at Harvard College. 



