192 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



April. — Under 18'1 cms. (7 in.) 10 %; over 209 cms. 



(7f in.) 40 % ; between 181 and 209 cms. 50 %. 

 May. — Under 18*4 cms. (TJ in.) 175 % ; over 21*4 cms. 



(8i in.) 32-5 % ; between 18'4 and 2T4 cms. 50 %. 

 June. — Under 17'3 cms. (6J in.) 15 % ; over 20'2 cms. 



(8 in.) 35 %; between 17*3 and 202 cms. 50 %. 

 July.— Under 18*6 cms. (7± in.) 18 %; over 2T5 cms. 



(8| in.) 32'5 %; between 18'6 and 21*5 cms. 50 %. 

 August. — Under 193 cms. (7| in.) 15 % ; over 236 cms. 



(9J in.) 35 % between 193 and 236 cms. 50 %. 

 September.— Under 193 cms. (7± in.) 15 %; over 23'8 



cms. (9^ in.) 35 %; between 19'3 and 23'8 cms. 



50 %. 

 October.— Under 18*7 cms. (7| in.) 10 % ; over 23'3 cms. 



(9J in.) 40 %; between 18'7 and 23'3 cms. 50 %. 



Tbe length distribution on these grounds resembles, 

 in general, that on the Nelson Buoy grounds further 

 North. The fish are, on the whole, a little larger: the 

 mode varies between 19'6 and 21 cms., the average being 

 about 20 cms., and the range over which 50 % of all the 

 fish, distributed equally on either side of the mode, are 

 caught is a little nearer to the larger end of the distribu- 

 tion than in the case of the Nelson Buoy grounds. 

 Otherwise we have to deal with a typical small-plaice 

 ground. It is also a ground which is not recruited from 

 other grounds harbouring a plaice population of the same 

 class, but one which receives its fish from the nurseries in 

 its immediate vicinity, that is, from the shallow water 

 grounds in the Estuaries of the Mersey and Dee. It 

 is not a stationary plaice population that we find here, but 

 one which arrives in successive shoals from other more 

 inshore regions where the rate of growth of the fish is less. 

 This is shown by the following Table : — 



