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MUSEUM OF COMPARATIVE ZOOLOGY. PA | 
relationship is closer between the jelly-fishes of these distant localities than 
between those of Narragansett Bay and the Bay of Fundy. The cause 
of this similarity may readily suggest itself to one who examines the 
direction of the currents of water which bathe the New England coast. 
The cold currents setting down from the Arctic have brought with them 
an assemblage of medusan genera of a facies in marked contrast with 
that of those brought into Narragansett Bay by warmer waters. This 
assemblage partakes of the characters of the Arctic, where the current 
has its birth. While it is true that some of the northern and boreal 
genera of medusze occasionally round Cape Cod and appear even in num- 
bers in the bays to the south of this headland, they show by their rarity, 
and their dependence upon the prevailing winds at the time, that their 
home is to the north.* 
Among familiar examples we might mention the well-known Cyanea 
arctica and Aurelia flavidula. Uardly a summer passes in which both 
of these genera are not found in Narragansett Bay near the Newport Lab- 
oratory, and sometimes the former are in great numbers. I have, how- 
ever, never seen them at Newport so large or so numerous as those which 
were taken almost every day at Eastport. Sporadic examples of Turris, 
Melicertum, and Staurophora are constantly taken in our surface fishing 
at Newport, but a few days at Eastport showed me a wealth of indi- 
viduals of these genera which was unknown to me before. This differ- 
ence in fauna exists also in the Physophores. Nanomia never ventures 
into Newport waters, and the magnificent Agalma seems to have its 
habitat on our coast limited to the southward of Cape Cod. 
If it were the purpose of this paper to contrast the pelagic medusan 
faune of the Bay of Fundy and Narragansett Bay, many other instances 
might be mentioned to show how different the jelly-fishes of the two 
* While there are many boreal medusz# which straggle into Narragansett Bay, 
a still larger number of those whose home is in the tropics make their way into 
our Southern New England waters through the agency of the Gulf Stream. The 
surface waters of the Gulf Stream are often blown nearer shore than is commonly 
supposed. I have noticed in the water near the Laboratory a rise in temperature 
_of over ten degrees in a single flood of the tide. The higher temperature of the 
water is a good sign that we are to expect oceanic animals in our dip-nets, and we 
are seldom disappointed. The cause of the elevation in temperature is thought to 
be directly connected with the prevailing wind from the southeast, where the Gulf 
Stream lies 
It is believed that the fact that the differences in the temperature of the water 
— now warmed by the Gulf Stream, now cooled by other currents —is what gives 
such a great variety to the marine fauna from Cape Cod southward. 
