124 FAUNA OF THE ISLES OF SCILLY. 



The Seco>t) Visit, 27tli April to loth May, 1903. 



On this visit I had the compauiousliip of Mr. E. Vallentin. 

 We made St. Mary's our headquarters, and conhned our attention 

 to the marine fauna of that island. We tow-netted from a small 

 sailing-boat or a rowing-boat, but as the weather was in an 

 unsettled state during the greater part of our visit, the days 

 suitable for working outside were somewhat few in number. 



As Hugh Town is situated on a narrow peninsula with the 

 harbour on the north side and Forth Cressa bay on the south, we 

 had the advantage of selecting the side most sheltered from the 

 wind. But we found that the harbour and its adjacent water 

 were not good places for tow-netting. The water is shallow and 

 usually very dirty, being full of small fi-agments of Zostera, 

 Algse, etc. It was better to work outside Forth Cressa, for there 

 the water is deeper, about 15-20 fathoms, and perfectly free from 

 dirt. The plankton too was greater in quantity and superior in 

 quality, owing to the excellent tide which runs off Feninnis 

 Head. 



The tow-nettings taken on our arrival clearly showed that 

 the season was a late one. The medusae, which usually occur 

 about the end of March in the English Channel, were not taken 

 until the beginning of May. 



Two nets were generally used. One with a half millimetre 

 mesh for the lower net, and the other smaller in size and of a 

 finer mesh at the surface. The results given in Fart I are based 

 on the contents of the lower net, which had by far the best catch. 

 The plankton found in the surface-net was identified by Mr. 

 Vallentin and the results are given at the end of Fart II. 



HYDEOMEDUS^. fSee also Talle II.) 



AlSTTHOMEDUSiE. 



AmpMnenm. nov. sp. — This new species has been taken at 

 Flymouth, and a description with figures is in preparation. 



Lipurena Jialterata. All specimens belonged to the earliest stage. 



Euphysa aurata. Young and intermediate stages. 



Hyhocodon prolifer, Agassiz. AU the specimens had medusa- 

 buds at the base of the tentacles. 



Lar sahellarmn. The few specimens taken all belonged to the 

 earliest stage. 



