l^ROWNB— Fauna and Flora of Valencia Harbour, Ireland. 685 



The quick disappearance of the large Ctenophores in the 

 autumn is, I believe, mainly due to gales and rough seas in 

 shallow water. The flimsy construction of Bolina renders it 

 specially liable to destruction by rough seas, but Beroe is less 

 so. Pleurohracliia is the least liable to destruction owing to its 

 shape, comparative smallness, and the firmer consistency of its 

 mesoglaea. 



Beroe apparently has only one generation in the year. Its 

 breeding season is during the summer months, when the adults 

 are so plentiful. The larval forms which survive the winter 

 probably live in deep water. They seek the surface early in 

 the summer, and are carried by surface cuiTents towards the 

 shore and by the tide into the harbour. 



Beroe ovata has a wide distribution. Large specimens 

 swarm off the Shetlands and the Hebrides, and also at times 

 at St. Andrews, during the summer. Haddon (1886) found 

 it exceedingly abundant off the west coast of Ireland. It 

 is apparently rather rare on the south coast of England. I 

 have only seen a few small specimens at Plymouth. 



EcHra-ODEKMATA. 



Larval forms, known as Pluteus, Bipinnaria, and Auricidaria, were 

 not uncommon during the spring and autumn, and at times were quite 

 abundant. 



Bipinnaria asterigera, Sars. 



Bipinnaria asterigera, M'Intosh, 1898, Ann. j^at. Hist. Ser. 7. 

 vol. ii., p. 105, pi. ii. 



A single specimen of this fine Bipinnaria was taken on 

 November 25th, 1895. It measured about 6 mm. in length, 

 and had twelve arms with corrugated margins. The Bipinnaria 

 carried a well-developed little starfish, which belongs to the 

 genus Luidia. 



Nemektea. 

 Pilidiutn. 



Two specimens of this larval form were taken in April, 1895. 

 Its occurrence may have been more frequent, as it is not 

 very likely that such a small and delicate form would be in a 

 recognisable condition in unassorted tow-net material sent a 

 long distance by post. 



3 B2 



