292 



COELENTERATA HYDROZOA 



systematic position in relation to each other and to other 

 Medusae has not been satisfactorily determined. 



Limnocodium sowerbyi is a small Medusa that was first 

 discovered in the Victoria regia tanks in the Botanic Gardens, 

 Regent's Park, London, in the year 1880. It has lately made 

 its appearance in the Victoria regia tank in the Pare de la Bete 

 d'Or at Lyons.i As it was, at the time of its discovery, the only 

 fresh-water jelly-fish known, it excited considerable interest, and 



Flo. 139. — Gonionema niurbachii. Adult Medusa, shown inverted, andoliuging to 

 the bottom. Nat. size. (Alter Perliins. ) 



this interest was not diminished when the peculiarities of its 

 structure were described by Lankester and others. It has a 

 rather flattened umbrella, with entire margin and numerous 

 marginal tentacles, the manubrium is long, quadrate, and has 

 four distinct lips. There are four radial canals, and the male 

 gonads (all the specimens discovered were of the male sex) are 

 sac-like bodies on the sub-umbrellar aspect of the middle points of 

 the four radial canals. In these characters the genus shows general 

 affinities with the Olindiidae. The difficult question of the origin 

 of the statoliths from the primary germ layers of the embryo and 

 some other points in the minute anatomy of the Medusa have 

 1 C. Taney et A. Conte, Zool. Anz. xxiv. 1901, p. 533. 



