344 BULLETIN OF THE BUKEATJ OF FISHEKIES 



Small specimens were again found there on May 4 (station 20120), in Ipswich Bay 

 on the 7th and 8th (station 20122); less numerously at the Massachusetts Bay 

 station (20124) and along Cape Cod (stations 20125 and 20126) on the 16th, and 

 one of 40 millimeters on Georges Bank on the 17th (station 20127). It is probable 

 that most of the Staurophora of that region are set free and reach recognizable 

 dimensions during the last week in April and the first week of May, for in 1913 we 

 found great numbers of the youngest stages in Gloucester Harbor on May 3 (Big- 

 elow, 1914a, p. 407). In favorable years a tremendous production of Staurophora 

 takes place in Massachusetts Bay, and the distribution of the adults suggests that 

 this is true of the western coasts of the gulf as a whole, if not for its whole shore line. 

 As yet, however, no search has been made for it in early spring anywhere north of 

 Cape Ann in the inshore waters where the medusa first appear, nor is it mentioned 

 in Doctor McMurrich's plankton lists from St. Andrews. 



Staurophora rivals the still larger scyphomedusae in the rapidity of its growth, 

 a fact long ago commented upon by Alexander Agassiz (1865) and more recently 

 by Hartlaub (1899), who kept the young medusas under observation for some weeks. 



By the middle of May the medusae attain a diameter of about 2 inches in the 

 Massachusetts Bay region, and during the last week of that month I have seen 

 specimens 3 to 4 inches in diameter cast up on the beaches of Cape Cod Bay in great 

 numbers. Staurophorse as large as 5 to 6 inches may be found early in June in 

 Massachusetts Bay, and they attain a diameter of 6 to 9 inches there during the 

 following month. 



Staurophora reaches sexual maturity later, and the medusae live until later in 

 the season in the northern part of its range than in the southern, paralleling the 

 differences of temperature with latitude. Thus, Mayer (1910) records mature indi- 

 viduals in Newport Harbor as early as the 5th to the 9th of June, 1895, while it is in 

 spring that Staurophora appears most commonly at Woods Hole. In Massachusetts 

 Bay it does not mature until early July, and our own experience corroborates Alex- 

 ander Agassiz's statement (1865, p. 137) that Staurophora vanishes thence by the 

 middle of that month, for we have found none there subsequent to that date. They 

 occurred very generally, however, and often in large numbers over the northern 

 half of the gulf, in deep water as well as shoal, during the last half of July and the 

 whole of August of 1912, a year of plenty (Bigelow, 1914, p. 123), while Fewkes records 

 it as common and of large size at Grand Manan during July and August, 1886, 

 particularly in sheltered bays near the north end of the island (Fewkes, 1888, p. 233), 

 and at Eastport until October. However, as we have not found it in September or 

 later, it is probable that few if any of the medusas of Staurophora survive much later 

 than the end of August in the open gulf. Thus Staurophora disappears from most 

 parts of the Gulf of Maine at least a month earlier in the season than either Aurelia 

 or Cyanea; and it is probable that when specimens are seen in the southwestern part 

 of the gulf as late as mid-August — for example, we noted it off Cape Ann and off 

 Cape Cod on the 24th and 29th in 1912 (stations 10042 and 10043)— they are not the 

 product of the shallows nearby but have drifted thither from the northern part of 

 the gulf with the general eddylike circulation. 



