6 DISCOVERY REPORTS 



the hook-like process at the base of the tentacle, emphasized by Vanhoffen as a characteristic structure 

 of his species. The peculiar four perradial and eight adradial nematocyst tracks on the exumbrella, 

 forming anastomoses towards the apex (described by Vanhoffen), are not seen in any of the specimens 

 observed by me. On the other hand, twelve meridional furrows run almost from the base to the 

 summit of the exumbrella; they do not branch, and there are eight adradial and four interradial 

 furrows, but no perradial. There is still the possibility that Vanhoffen's description is misleading and 

 if so E. valdiviae must be regarded as an obsolete species. 



Distribution. The original specimen was taken south of the Newfoundland Bank; I have seen 

 several specimens from other parts of the Atlantic Ocean, and one of the Discovery specimens was 

 taken in the Indian Ocean, off the coast of East Africa. 



Euphysora gigantea sp.n. 

 (PI. I, figs. 3,4) 



Occurrence: St. 78. 12. vi. 26. 35° 18' 00" S, 19° 01' 10" W. South Atlantic. Net: TYF looo(-o) m. i specimen. 

 St. 1972. 28. ii. 37. 52° 11' S, 52° 33' 42" W. East of Falkland Islands. Net: TYFB 2100-1400 m. i specimen. 

 St. 1995. 13. iii. 37. 61° 21' 06" S, 25° 49' 12" W. South of South Sandwich Islands. Net: TYFB 1 800-1 300 m. 



3 specimens. 

 St. 2001. 16. iii. 37. 67° 04' 24" S, 19° 41' W. Weddell Sea. Net: TYFB 1750-1300 m. 2 specimens. 

 St. 2006. 19. iii. 37. 66° 16' 42" S, 13° 23' 18" W. Weddell Sea. Net: TYP'B 1750-1400 m. 4 specimens. 

 St. 2008. 20. iii. 37. 66° 06' 30" S, 06° 45' 36" W. Weddell Sea. Net: TYFB 1 500-1 300 m. 2 specimens. 



Size of the specimens 

 Station 78 1972 1995 2001 2006 2008 



Height (mm.) 17 20 17 22 23 26 26 ii 19 23 



12 



Diam. (mm.) 17 18 17 22 23 28 28 8 19 23 8 12 



The specimen, 23 mm. high and wide, from St. 1995 is chosen as the holotype. 



Description. Umbrella about as high as wide, globular, the gelatinous substance very thick, 

 umbrella-cavity narrow, about half as high as the umbrella. Manubrium cylindrical or slightly 

 barrel-shaped, its length one-half to two-thirds that of the umbrella cavity, surrounded from its base 

 almost to the distal end by a ring-shaped gonad, leaving only a short cylindrical mouth tube. Mouth 

 opening simple, circular, with a slightly everted margin. No apical canal. Four radial canals and 

 ring-canal moderately broad, their endodermal cells not vacuolated. Velum narrow. Only one mar- 

 ginal tentacle, no rudimentary bulbs in the three other perradii. The tentacle has a well-developed 

 conical basal bulb; the tentacle is very long and thin, carrying several bifurcated lateral branches 

 separated by long intervals. 



In most of the specimens the tentacle is lost, and even in the best preserved specimen (the type) 

 the distal end is lacking, so that the full length of the tentacle remains unknown. In the type specimen, 

 the number of lateral branches in the existing part of the tentacle is seven, increasing in size from the 

 basal towards the distal part. Each branch consists of a basal trunk and two diverging branches of 

 about the same length as the trunk. The tentacle is hollow with a fairly thick mesogloea. The ecto- 

 dermal epithelium has entirely disappeared, so that the distribution of the nematocysts cannot be 

 determined. The endodermal cells of the bifurcated branches contain protoplasm and nuclei (PI. I, 

 fig. 4) ; presumably they have carried nematocysts, but none of these are left. 



According to notes on some of the labels, the colour of the manubrium and the radial canals is a 

 bright, brilliant, deep orange. 



