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BrLLETIX: MUSEUM OF COMPARATIVE ZOOLOGY. 



for it is quite as abundant in the Atlantic water south, as in the Arctic 

 water north, of Iceland (Paulsen, 1909, p. 42, Murray and Hjort, 

 1912, p. 107); and is common south of Ireland (Massy, 1909). The 

 true explanation is that though Clione reaches its maximum size, and 

 abundance in Arctic waters, its normal range reaches the northern 

 boreal waters as well. In the Gulf of Maine it is probably endemic 

 in small numbers which may receive additions annually from the 

 north. 



Two other species of pteropods were taken in the Gulf of Maine in 

 1914, a Pneumoderma too young for specific determination (Station 

 10245) ; and two specimens of Limaciria inflata off Cape Cod (Station 

 10213), the latter no doubt stragglers from the south. 



The stations on the continental slope, on Georges Bank, and off 

 Marthas Vineyard, yielded the following tropical pteropods and 

 heteropods (identified by W. F. Clapp): — 



Pclnf/ic Coelentcratcs. The Medusae, Siphonophorae, and Cteno- 

 phorac taken on the cruises of 1914 and 1915 fall into two well-marked 

 geographic groups, Boreal-Arctic, and Tropical. The records for the 

 former for 1914 are given in tlic following table: — 



