124 bulletin: museum of comparative zoology. 



with in Massachusetts Bay, at the off-shore Stations (27, 28), in the 

 Eastern Basin nor on German Bank (Stations 29, 30). Its absence 

 off shore is not surprising, because it is undoubtedly neritic ; but its 

 absence from Massachusetts Bay is less easily explained, because it 

 is often very abundant there in May and June. The known salinity 

 at which it was taken ranges from 32.5%o to 32.7%o, the known temper- 

 ature from 50°-64°, all being surface records. But most of the actual 

 specimens taken came from intermediate hauls with open nets; and 

 this was notably so at Stations 14, 15, 19, 25, 36, 41, and 43, where 

 none were taken or seen on the surface. And the Staurophorae seen 

 floating were usually from | to 2 fathoms down, seldom on the actual 

 surface as Aurelia so often is. None were taken in closing nets. Our 

 records do not suggest that Staurophora is restricted to cold waters; 

 but probably the young stages are more sensitive to temperature. 



Aurelia and Cyanea (Plate 6) can be considered together, as the 

 Gulf of Maine, unlike the Norwegian Sea, has only one species, or 

 variety, of Cyanea, which is not a migrant from elsewhere, but a per- 

 manent inhabitant, breeding and going through its young stages here. 

 As might have been expected, both these Medusae were most numer- 

 ous near shore, Aurelia particularly so in the bays and harbors; and 

 they are so large and conspicuous that they are easily seen on the 

 surface, even if not taken in the net. 



In Massachusetts Bay, early in July, we saw many Aurelia, though, 

 as it chanced, no Cyanea; but on our return thither at the end of 

 August, both genera were seen floating on the surface at various spots 

 between Gloucester and Provincetown. During our work along the 

 coast between Cape Ann and Portland, the two genera were frequently 

 recorded, both in the nets and on the surface, both of them being 

 generally distributed in the coast waters in this region. But on the 

 run to Piatt's Bank we left them behind at about Lat. 43° 15', long. 

 69° 50', and saw and took neither of them on the course thence to 

 Jeffrey's Bank (Station 25) or until approaching the mouth of Penob- 

 scot Bay, where (Station 26) both species once more appeared on the 

 surface. Similarly on the run from Cape Elizabeth toward Nova Scotia 

 the last Aurelia was seen at about 69° long. 43° 30' lat., and neither 

 genus was found until we approached the coast again between Mt. 

 Desert and Grand Manan. In the Grand Manan Channel, at East- 

 port, and during the run westward along the coast, both were seen 

 frequently, except at Stations 38 and 39. But neither species was 

 encountered anywhere in as great abundance as they are often seen, 

 except off Cape Cod, on August 29, when Aurelias were passed in 



