28 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



the control nets without illumination. The Crustacea captured 

 in the net with the electric light were mainly Amphipoda, such 

 as Ampelisca Icevigata and Dexamine vedlomensis, and certain 

 Cumacea (Cuma scorpioides, Iphino'e trispinosa and Pseudo- 

 cuma cercaria), which are rarely met with in quantity. Mr. 

 Walker pointed out in his report that all the Cumacea taken 

 both at Ramsey Bay and Port Erin were males, and that the 

 probable reason is that the males of all the three species repre- 

 sented are provided with pleopoda (or swimmimg legs), while 

 -the females are not, and that consequently the males are no 

 doubt more active swimmers, and, therefore, more likely to 

 rise from the sea-bottom where they live. In the illuminated 

 surface nets the remarkable feature was the quantity of Cope- 

 poda, which were identified and reported upon by Mr. Isaac 

 Thompson. Apart from the considerable number of species 

 added to our faunistic results by this expedition, the 

 " Hysena " cruise of May, 1888, is note-worthy on account 

 of the successful application of the electric light as an 

 attraction in both surface and bottom nets worked after dark. 

 This matter was carried further in a five days' cruise 

 round the Isle of Man at Easter, 1889, when a considerable 

 number of rare and interesting Crustacea (chiefly Schizopoda, 

 Cumacea and Amphipoda) were captured. The large number 

 of Cumacea, and especially adult males of Iphino'e trispinosa 

 was a marked feature, not merely in the bottom nets, but also 

 at the surface, in an area which had been illuminated by the 

 electric light for half an hour before the nets were put over. 

 In none of the daylight tow-Dettings, either bottom or surface, 

 was a single Cumacean obtained, while every gathering on the 

 two nights when we had the electric light in operation contained 

 Cumacea in abundance. Full details of the matter are given in 

 our third Annual Report. That free-swimming Crustaceans are 

 attracted to a stationary net by the electric light may now, 

 after our experiments of 1888 and on this last cruise, be con- 



