MEDUSJE. 11 



In 1908 Prof. Bedot publislied a description of a new Coelenterate from the 

 Antarctic under the name of Wmiddin Charcot i ; with liis assistance I liave l)ecn able 

 to show that it belonfjs to the genus Eleufhcrin. 



I have been able to confirm Dr. Vanhotfen's statement that the tentacles described 

 by Dr. Rennie as belonging to large Antarctic Siphonophorea are the tentacles of 

 a Desnwnenui. 



HYDEOMEDUS^. 



ANTIIOMEDUSiE. 



Family CODONID^ 



Margelopsis, Hartlaub, 1897. 1907. 



Generic Character. — Codonidae with four perradial groups of tentacles, each with 

 two or more tentacles ; with four radial canals ; with gonad encircling the stomach. 



^Iargelopsls australis. 

 (Plate IV., figs. 6 and 7.) 



Description of the Species. — Umbrella bell-shaped, about as broad as high. 

 Ex-umbrella covered with nematocysts which are not arranged in groups. Stomach 

 cylindrical, nearly as long as the umbrellar cavity. Mouth circular. Four radial 

 canals. Gonad completely encircles the stomach and forms a conspicuous globular 

 swelling. Four perradial groups of tentacles, each group containing two small tentacles, 

 placed one behind the other. 



Size. — Umbrella about 0'75 mm. in width. 



There is only one specimen of this little Medusa in the ' Discovery ' collection. 

 It was taken on the 29th May, 1903, in Mc^Murdo Sound. The specimen very clo.sely 

 resembles }far(ji'lopsis harthiuhi, Browne (1903), which inhabits the Qords of Norway 

 in the neighbourhood of Bergen. I have not succeeded in finding a good reliable 

 character for di.stingui.shing the Antarctic species from M. hartlaubi ; this is partly 

 due to the minuteness of the specimen, and to its somewhat contracted and crumbled 

 condition. 



When the specimens from Norway and the .Antarctic are placed side by side they 

 look like two distinct species, but the different appearance is mainly due to the shape 

 of the umbrella, and to the much larger size of the Norwegian .specimen. 



The ex-umbrella of Murtjilopsis hartlaubi is covered with nematocysts which are 

 grouped together into clusters, each cluster containing about a dozen nematocysts. 

 The ex-umbrella of Marijelopsis australis is covered with isolated nematocysts which 

 are not arranged in groups. The stomach of M. hartlauhi has a very thick quad- 

 rangular ba.se, which is situated in the jelly above the top of the umbrellar cavity. 



VOL. V. X 



