^^0 ON THE CRUSTACEAN FAUNA OP A 



On the Crustacean Fauna of a Salt-water Pond at Ai?ihle. 

 By G. Stewardson Brady, M.D., LL.D., D.Sc, F.R.S. 

 (Plates 9 and lo). 



At Amble, immediately south of the mouth of the Coquet, is 

 an old disused quarry separated from the sea by a narrow wall 

 of rock through which, by means of a small opening, it 

 receives intermittent supplies of sea-water at the time of high 

 tides ; and during stormy weather, especially with an east 

 wind, the sea is liable to break in considerable volume over 

 the intervening rampart of rock. In this way the quarry has 

 been filled with sea-water, whose level varies to a small extent 

 with the rise and fall of the sea. There is no influx of fresh 

 water other than mere surface drainage, and the water of the 

 quarry has thus, by evaporation, become more salt than that 

 of the sea outside. The depth of water is about fifty feet at 

 the south-eastern end of the pond ; thence it decreases rapidly 

 to the north-western end, which is shallow and shelving. The 

 whole area of the pond is about one acre and a quarter. 

 There is very little vegetation — nothing but a scanty growth 

 of small brown algae (Ectocarpus ?) and some Confervae. The 

 quarry was disused about fifty years ago, and since that time 

 has been allowed to fill with water : it is therefore within a 

 comparatively short period that the existing fauna must have 

 been selected and adapted to present conditions. 



The bottom consists of sandy mud with many stones in the 

 deeper part, and of shelving rock at the shallow end. Fishes 

 such as plaice, dab, flounder, eel, and even herring have 

 been occasionally caught, and with a view to further investi- 

 gation Mr. Meek planned a visit to the quarry during 

 November of last year (1905). I was to have accompanied 

 him, but was unable to do so owing to inclement weather, 

 and the necessity of rising earlier in the morning than I found 

 quite agreeable. The scanty proceeds of some netting and 

 dredging were, however, submitted to me by Mr. Meek, and 

 proved so interesting that I made an excursion to the pond in 

 December in order to obtain further material for examination. 

 When one considers the small amount of interchange which 



