54 THE ZOOLOGIST. 



COROPHIUM LONGICORNE : AN OKNITHOLOGICAL 

 STUDY OF A CEUSTACEAN. 



By F. J. Stubbs. 



During the summer of 1913 I spent some weeks as the guest 

 of Mr. J. Franklin Kershaw at his house on the Kent Estuary, 

 in Westmorland ; and, as the garden where we spent much of 

 our time reaches down to the tide-mark, I was able to make a 

 long series of connected observations on the animal life of the 

 sands. Besides the wide areas of vegetated salt-marsh, there is 

 a great stretch of level sand which is covered by the sea only 

 during the highest tides once a fortnight ; and in each intervening 

 fourteen days there is a period of over a week when the shore is 

 never covered and remains quite dry. 



For my present purpose I took an area of one square mile of 

 sand lying between Arnside and Sandaide. The sand here is 

 somewhat muddy, and, between the tides, unusually firm and 

 smooth of surface. A motor cycle (as I noticed one day) leaves 

 a mark no more than an eighth of an inch deep ; yet, when I 

 held an ordinary garden spade upright on the dry sand at the 

 edge of a pool, and rocked the handle gently from side to side 

 without applying any downward pressure, the implement in less 

 than a couple of minutes sank so deeply that it could not be 

 withdrawn by a direct pull. These remarkable quicksands, 

 which occur on many parts of this coast, sometimes collapse 

 beneath one's feet in an alarming manner, although a moment 

 before the surface had been hard, dry, and apparently solid. 



This square mile of firm level sand in front of the house — 

 and I exclude now the salt-marsh, the permanent pools, and the 

 regular channel of the river — supports a wonderfully simple 

 invertebrate fauna and practically no plants. Once or twice I 

 noticed a faint green tinge over a few square inches of sand, 

 possibly due to the alga Halosphcera ; and, very rarely, a few 

 fronds of Fucus were left behind by the tides. The molluscs 



