MARINE BIOLOGICAL STATION ON PUFFIN ISLAND. 37 



rest upon two studs projecting laterally from the sector of 

 an escapement wheel near its circumference. The lengths 

 of the levers are so adjusted that when the first tooth of 

 the escapement is liberated one of them falls, whilst the 

 second is retained until the third tooth has been liberated. 

 The escapement sector is actuated by a spring, and its 

 movements are controlled by an electro-magnet, whose 

 armature is attached to, or rather made solid with, the 

 escapement itself. The current passes to the magnet 

 down a wire in the rope by which the net is towed, and 

 when the net is let down closed the circuit is open. As 

 soon as the desired depth has been reached contact is made, 

 the movement of the armature releases the first tooth of 

 the escapement, and the net opens. When the circuit is 

 broken the second tooth of the sector is caught by the 

 escapement, and held until a second contact sets free the 

 other lever and closes the net. 



A further contemplated improvement is the combina- 

 tion of this electric opening and closing tow-net with the 

 electric illuminated tow-net which we have now used dur- 

 ing several successive cruises of the " Hyaena." A small 

 incandescent lamp will be placed in the mouth of the net, 

 and the same current will be used for causing the move- 

 ments of the net and for supplying the light. 



Several hauls of the dredge were taken during the after- 

 noon in Carnarvon Bay on a sandy bottom, at depths of 

 12 to 20 fms., in which, amongst other things, Ascidia 

 plebeia, a Holothurian, Leda yernula, Astarte sulcata, Acmcea 

 testudinalis, and Pandora incequwalvis were obtained. The 

 " Hyaena" anchored for the second night in a small rocky 

 bay, Porth Dafarch, on the south side of Holyhead Island 

 (close to where the s.s. " Missouri" was wrecked a few 

 years ago), and about half the party were landed to sleep 

 on shore. After dark, those who remained on board com- 



