BY R. VON LENDENFELD, PH.D. 585 



Colour : Perisarc reddish brown. 



Size : Height of stem, 2-3 mm. Length of Hydranth, 

 0-6—0-8 mm. 



Ontogenesis : I have bred the Medusae from the Syncoryne- 

 Polyps in the Aquarium, but have not been able to obtain adult 

 Medusae. 



Locality : Laminarian zone. Port Jackson, on buoys and sub- 

 merged ropes. 



Note : I have always found this species together with Obelia 

 geniculata, and over-growing the latter, cpaite hidden by the 

 long stems of the Obelia, it doubtlessly derives great protec- 

 tion from its neighbour. I think it by no means impossible that 

 it is a parasite on the Obelia, and that it extracts its food from 

 the Hydrorhiza of the Obelia. I hope to be able to decide this 

 interesting question in another paper. 



Season : Medusae are produced in April and May. 



34. GENUS DICODONIUM. Haeckel. 



The Medusae are Codonidae with two opposite tentacles. On 

 the vortex of the Umbrella there is a conic Gallert protruberance 

 with axial canal. Manubrium short, scarcely projecting beyond 

 the orifice of the Umbrella. The Polyp colonies are unknown. 



179 DICODONIUM DISSONEMA. Haeckel. 



Haeckel (1) obtained this Medusa, the Ontogenesis of which is 

 unknown, from Australia. 



35. GENUS EUPHYSA. Forbes. 



Codonidae, with three tentacle rudiments and one well developed 

 arm. Umbrella regular and bilateral (excepting the larger dorsal 

 ocellar bulbe). 



(1) E. Haeckel. Das System der Medusen. Seite 28. 



