Browne — Fauna and Flora of Valencia Harhour^ Ireland. 705 



Porbes first found. Slaiheria haUerata in Mounts Bay, Corn- 

 wall, in 1836, and described tbe species witb one large terminal 

 cluster of nematocysts on eacli tentacle. Off Mnll, in 1 85 1 , Forbes 

 fonnd some specimens of tbe same genus having, in addition 

 to tbe terminal cluster, five to six rings of tbe nematocysts on 

 tbe lower balf of eacb tentacle. He regarded tbe presence of 

 tbe rings as a specific cbaracter, and described a second species 

 under tbe name of S. catenata. In otber details tbe Mull speci- 

 mens agree fairly well witb tbe first-named species. Tbe speci- 

 mens taken at Yalencia sbow tbe connexion between tbe two 

 species of Porbes ; and I consider 8. catenata to be tbe fully 

 developed adult stage of ;S^. halterata. 



All tbe Yalencia specimens bave tbe peculiar linear swellings 

 upon tbe four radial canals ; tbey bave tbe appearance of im- 

 mature gonads. In tbe adult tbe generative cells are arranged 

 in large clusters upon tbe manubrium. 



Alnormal specimen. — One specimen, taken in July, 1898, bad 

 an interesting abnormality, wbicb I bave not seen before among 

 tbe Sarsiadse. 



Tbere was an extra tentacle attacbed to one of tbe four 

 normal tentacles. It was like its companion in size ; but its 

 basal bulb was smaller, and joined to its neigbbour. Tbe 

 ocellus was very small, faintly coloured, and only just visible. 



Ectopleura dumortierii (van Beneden). 



Uctopleura dumortierii, Hincks, 1868, p. 124, pi. xxi. 



In 1895-96, not a single specimen was taken. 



In 1897, tbe Medusa appeared at tbe end of April and dis- 

 appeared early in October. Usually one or two specimens were 

 taken on eacb day of tow-netting. On April 27tb, nine 

 specimens were taken ; tbe smallest about 1 mm. in diameter, 

 and tbe largest 4 mm. in lengtb and 2J mm. in widtb. Speci- 

 mens witb ova were taken in May. 



In 1898, it was foimd from Marcb to June; usually very 

 scarce. 



Tbis Medusa is liberated from tbe rare Hydroid Ectopleura 

 dumortierii^ wbicb. bas only been twice recorded : by Van 

 Beneden at Ostend; and by Hincks, wbo found it on drift- 

 wood cast asbore at Point of Ayr, Isle of Man. The fi-ee- 

 swimming Medusa bas been taken at Heligoland (Hartlaub) ; 

 St. Andrews (Crawford) ; Plymouth (E. T. B.). 



