BIGELOW : THE " GRAMPUS " IN THE GULF STREAM. 203 



It is evident, then, that the bulk of the catch was obtained by 

 the net on its downward and upward trips through the surface zone- 

 None of the genera of fishes, of crustaceans, of holothurians, nor of 

 Medusae, which have been shown to be characteristic of the intermedi- 

 ate zone, were taken. This is the more remarkable in view of the fact 

 that two intermediate genera of Medusae, Atolla and Periphylla, have 

 both been taken frequently in the trawl from the region of the Gulf 

 Stream. I am unable to explain this failure. It may be that we did 

 not work deep enough, and this occurred to us during the Cruise, but in- 

 asmuch as our apparatus was not adapted to working at depths greater 

 than 300 fathoms, we were unable to test this possibility. However, 

 the experience of the " Albatross " expedition to the Eastern Tropical 

 Pacific has demonstrated, for the region of the Humboldt current at 

 least, that the intermediate fauna is abundantly represented in the zone 

 above the 300-fathom line, and I see no reason to believe that the con- 

 trary would prevail in the Gulf Stream, a region in which, although 

 temperate conditions are different, the nature of the food supply of inter- 

 mediate organisms much resembles that in the Humboldt current. It is 

 not improbable that had we worked a month later our success might 

 have been greater. 



In spite of the general poverty of the intermediate fauna, one new in- 

 termediate Medusa, a Sibogita, was taken. It is of interest not only from 

 the systematic standpoint, but also from the circumstances of its capture. 

 Sibogita was first taken at Station 3, where six specimens were captured 

 in a haul with the five-foot net from 175 fathoms. At this point, which is 

 on the coastal slope, the depth of water is about 260 fathoms, and from 

 here the slope to the 1,000-fathom curve is rapid. Sibogita was not en- 

 countered again until Station 11, when, at about the same relative posi- 

 tion on the slope, in a depth of 300 fathoms, another specimen was 

 taken in a haul from 150 fathoms. The species was not met with again, 

 although another haul was made near the locality where it was first cap- 

 tured. There is every reason to believe, from its near allies, that Si- 

 bogita passes through a fixed stage ; and from the present captures I 

 believe that when discovered the hydroid will be found to be a deep- 

 water form, living below 150 fathoms. The fact that this Medusa has 

 never been recorded from Woods Hole or from Newport, in spite of the 

 systematic collecting carried on for many years at both these localities, 

 is no doubt due to its intermediate habitat, below the influence of the 

 surface waters of the Gulf Stream which are often driven by southerly 

 winds against the southern coast of New England. 



