MEDUSA. 3 



The collection made by the 'Southern Cross' in 1899-1900 came from the 

 neighbourhood of Cape Aclare (lat. 70 18' S., long. 170 9' E.). Some of the 

 specimens were collected during May, 1899, and others during November and 

 December, 1899, and January, 1900. The surface temperature of the sea on the 

 10th May, 1899, was 27 F., on the 13th Sept., 28'6 F., and during the summer 

 months December, January and February it rarely rose above 32 F. During the 

 winter months the temperature of the sea under the ice remained constant at 27 - 8 F. 



Most of the specimens were taken in tow-nets or dredges in shallow, open water 

 not far from shore, and a few were picked up after having been washed ashore. 

 Unfortunately, the specimens were not sufficiently preserved, and were badly stored in 

 bottles or tins ; consequently they nearly all arrived home macerated and damaged. 

 It was, undoubtedly, a stroke of good luck that two out of three of the species peculiar 

 to the ' Southern Cross ' collection happened to be in good condition. 



A preliminary account of the Hydrozoa of the ' Southern Cross ' Expedition was 

 published by me in 1902. It was based upon a rapid survey of the collection, and 

 abstracted from a manuscript written for the benefit of Mr. Hodgson, who was then 

 about to sail in the ' Discovery.' The preliminary account carries no priority, as none 

 of the species were named. 



The ' Discovery ' collection was made under conditions totally different from those 

 of the ' Southern Cross ' collection. Nearly all the specimens were captured in nets 

 which were let down through holes in the ice. Owing to the low air temperatures the 

 plankton on being placed in the collecting bottles froze in winter at once, and had to 

 be thawed out on board ship. In summer the water in the bottles was generally full 

 of ice crystals which, with the jolting of the sledge as it travelled shipwards, cut the 

 more delicate animals to pieces (Hodgson, 1907). When Medusae are collected under 

 such severe conditions one must not be surprised at seeing damaged specimens. 



The 'Discovery' was held fast in the ice for two years (March, 1902, to February, 

 1904) in McMurdo Sound (lat. 78 49' S., long. 166 20' E.). This sound is between 

 the mainland of South Victoria Land and Eoss Island, upon which the volcanoes 

 Erebus and Terror are situated. The sound is converted into a bay at the southern 

 end by Ross's Greaflce Barrier. At the barrier end the sound is over 400 fms. deep, 

 but over the area covered by Mr. Hodgson's collecting the water is from 5 fms. to 

 180 fms. deep. Beneath the ice a current flowed through the sound in a 1 'south-easterly 

 direction. The temperature of the sea beneath the ice ranged from 2 8 '4 F. in winter 

 to 30 F. iu summer. 



VOL. V. 



