342 
BULLETIN OF THE BUREAU OF FISHERIES 
on Mount Desert Island; and in the bays of Grand Manan, where Fewkes found 
it one of the commonest medusae in the summer of 1886 and I, myself, in August, 
1910. Its breeding period endures from mid-July throughout August or even later, 
both in Massachusetts Bay and in Penobscot Bay, hence is no doubt uniform along 
the whole coast line of the gulf. The eggs are shed freely, are easily fertilized 
artificially, and the early stages in development can be followed without difficulty. 
I have not seen Melicertum after August, but A. Agassiz (1865, p. 181) 
describes it as plentiful in Massachusetts Bay “in the fall at the time of spawning.” 
How late in the season its medusae may survive is not known. Perhaps it appears 
and dies earlier in the southwestern than in the northeastern part of the gulf, like 
Staurophora. 
It is probable that the hydroid stage of Melicertum is invariably passed in the 
immediate neighborhood of the coast, there being no evidence that this ever takes 
place on Georges or Browns Banks or even on offshore ledges within the gulf, such 
as Cashes and Platts. And while the adult meduste occasionally drift out to sea 
(for we have taken odd specimens over the western basin on August 9, 1913 (station 
10088) and near Mount Desert Rock (station 10248) on August 13, 1914), it is very 
seldom that one strays beyond the 100-meter contour; nor have we ever found 
Melicertum in numbers anywhere outside the bays, river mouths, or harbors, except 
off Cape Cod and near Browns Bank (p. 33, footnote). 85 
Staurophora mertensli, Brandt 
This is a boreal Arctic species, circumpolar in its distribution, ranging widely 
over the Arctic Ocean and adjacent parts of the North Atlantic, and also in the 
North Pacific. In the eastern side it is known from many localities about Iceland, 
from Spitzbergen, Nova Zembla, the White Sea, all along the west coast of Norway, 
between Scotland and Iceland, and from the northern part of the North Sea. 88 In 
the western Atlantic and its tributaries Staurophora has been recorded from the 
west coast of Greenland, from the east coast of Newfoundland, from many localities 
in the Gulf of Maine, as detailed below, at Woods Hole, and as far westward along 
the south shore of New England as Newport (Mayer, 1910) and Fisher’s Island 
Sound (Verrill, 1875, p. 43). Its known range in the North Pacific area includes 
Bering Sea, the Aleutian Islands, and the coast of Alaska on the east, and Japan on 
the west; and if Kramp’s (1919, p. 41) contention that the S . falklandica of Browne 
(1902) from the Falkland Islands is actually S. mertensii proves correct, it is bipolar. 
This large hydromedusa is a very conspicuous member of the plankton of the 
Gulf of Maine during its periods of plenty, for it attains a diameter of upwards of 
200 millimeters at maturity and is made easily recognizable by its white central 
cross. It has not been actually demonstrated that Staurophora passes through a 
hydroid stage, but its systematic relationships and its seasonal history, outlined 
below, make it practically certain that such is the case. 
“ For locality records of Melicertum during the summer cruises of 1912 to 1914 see Bigelow, 1914, p. 125; 1915, p. 316; and 1917 
p. 303. 
88 Kramp (1919, p. 44), who has plotted its distribution in the northeastern Atlantic, has shown that the young “Staurophora” 
described by Hartlaub (1899) from Helgoland probably was not this genus, but that the S. discoide a described by Kishinouye 
(1910) from Japan is not distinguishable from S. mertensii. 
