L.M.B.C. MEDUSA. 405 



as I know has not been recorded for Europe. A. Agassiz 

 gives an excellent description of the life-history of this 

 species and also a description of its hydroid. 



Umbrella flatly-arched, about twice as broad as long, 

 stomach flat ; mouth with crenate lips. Four radial canals. 

 The gonads extend nearly along the whole length of the 

 canals, starting from stomach and reaching nearly to the 

 margin, forming in the adult specimens a folded band. 

 On the margin of the umbrella 100 to 200 tentacles. 

 Between these tentacles there are short filiform cirri, and 

 also club-shaped cirri. No marginal vesicles. In the 

 basal bulb of the large tentacles there is a black ocellus. 

 The largest specimens are about an inch in diameter. 

 Umbrella and tentacles colourless. Ovaries yellowish. 

 The Port Erin specimen is only 5 mm. in diameter, with 

 about 30 tentacles, and cirri of both shapes. It corresponds 

 to the description given by Agassiz. It is certainly not 

 Laodice cruciata. 



Agassiz obtained his specimens in Buzzard Bay, North 

 America, 1861. 



Melicertidium octocostatum, (Sars 15). 



Stomoh'achium octocostatum, Forbes (9). 



Two specimens taken at Port Erin on May 27th, and 

 one on June 2nd, 1893. Forbes describes the tentacles as 

 being uniform, but Ehrenberg and Eomanes (19) have 

 seen a small tentacle between two large ones. The Port 

 Erin specimens have also one small tentacle, sometimes 

 two, between every pair of large tentacles. 



This species may easily be identified by the eight radial 

 canals. 



Distribution. — Norway, Cromarty Firth, Ireland (N. 

 \V. Coast), Bute, Arran, St. Andrews. 



