34 SALT-WATER FISHES 



after the spawning is over in order to find fresh supplies of 

 food to satisfy their ravening appetites. The shore-haunting 

 kinds may more particularly be classified under the two 

 categories already named, sand-fish or rock-fish, and it will be 

 found on investigation that the majority of them are, in view 

 of the aforementioned risks of the shallow and disturbed 

 water, capable of affixing themselves when threatened with 

 dispersal. Of the rock-fish, the suckers (^Lepadogaster, 

 Liparis, etc.), and in a lesser degree the gobies {Gobius\ 

 illustrate this power ; while, among the others, we have the 

 flat-fish (Heterosomaia) and weevers {Trachinus), which lie half- 

 covered by the sand, or even with only the eyes and gills 

 protruding, and the sand-eel and launce (^Ammodytes), which 

 burrow beneath it.* 



IV. Equally unsatisfactory in many respects is any attempt 

 to separate the surface-swimming from the ground-dwelling 

 fishes, for here also there is an even greater interchange than 

 between those inhabiting coastal and more open waters. It is 

 matter of common knowledge, as already stated, that the 

 shoals of mackerel, which during the greater part of the year 

 are encountered at, or near, the surface, break up and sink to 

 the bottom at the end of summer. At the same time, bearing 

 in mind these difficulties, we can, of course, distinguish, if it 

 so please us, between the characteristic surface-fishes of our 

 seas — the mackerel {Scomber), herring {Clupea), bass {Labrax), 

 grey mullet (Mugil), and so on — and those which, on the 

 other hand, pass the greater portion of their existence close to 

 the bottom, such as the angler-fish {Lophius), skates [Rain), 

 weevers {Trachinus), ling {Molva), and others. It will, more- 

 over, be found that it is more usual for the normally surface- 

 fishes to spend a period at the bottom than for the pronounced 

 ground-dwellers to appear in any numbers or for any consider- 



* See an interesting article by Hunt and Jeffreys in the Jouni. Linn. 

 Soc, 1885 (pp. 262-274, and particularly pp. 270-271), entitled, "On 

 the Influence of Wave-currents on the Fauna inhabiting Shallow Seas." 



