THE FLAT-FISHES 223 



in the months of March and April, though in some localities 

 it may begin to spawn as early as February, while in others 

 it may not have finished until early in June. It is one of the 

 fish that spawn regularly in the Plymouth tank-house, between 

 the beginning of March and the beginning of May. The 

 natural spawning-grounds are not more than about 10 miles 

 from land, in water of 30 fathoms or less. 



,The egg of the flounder measures in diameter rather less 

 than ^ in., and is therefore intermediate in size between those 

 of the plaice and dab. It is round and transparent, has no 

 oil-globule, and floats in the water. At a temperature of 

 about 53° F. it hatches in seven days after fertilisation. 

 The larva measures about -^ in., and has black and yellow 

 spots on the head and body. These presently cover the fins 

 and tail, the latter in a broad band. Professor Mcintosh has 

 recorded an interesting fact in the early history of the flounder. 

 He found some years ago that the post-larval form, measuring 

 perhaps an inch in May, is preyed on by sparrows that seize 

 it in the shallow rock-pools left by the ebbing tide. The 

 flounder, even at that early age, while still transparent, 

 evidently shows that preference for estuaries and the neigh- 

 bourhood of land generally which clings to it through life, 

 save only when the demands of its pelagic egg compel it to 

 seek the denser, deeper water outside. 



The Lemon Dab (P. microcephalus), or Lemon Sole,* 

 is of a warm yellow colour mottled with dark and light spots. 

 In shape it is more exactly oval than any other British flat-fish 

 of either the sole, plaice, or turbot group. The scales are very 

 small and smooth, so that the lemon dab feels slimy to the 

 touch, and they cover the entire fish, even the upper surface 

 of the fins. The lateral line is only slightly curved behind the 

 head. The head itself is small ; the mouth also is small, and 

 the teeth are blunt and more developed on the " blind " side. 



* This must not be confused with a congener of the true sole, 

 Solea lascaris, also called by this name. 



