SEA-FISHERIES LABORATORY. 191 



be caught easily in the sand-pools left by the receding tide. 

 These little plaice, at the end of May or the beginning of 

 June are about 1-2 cms. in length on the sandy beaches in 

 the Mersey Estuary. They, and other Pleuronectid fishes 

 of about the same age, feed greedily here on copepods — 

 mainly Temora, so that occasionally 50 to 100 of these 

 micro-crustacea may be found in the stomach of a single 

 fish, and at this age it is often the case that the larvae of 

 an Appendiculate Trematode may also be found among 

 the copepods. When they are a little larger copepods are 

 not so commonly found in their stomachs, but Polychaet 

 larvae become very common, and occasionally larval 

 shrimps may also be found. Sometimes (on other parts of 

 the Lancashire coast) larval Gastropods (probably the 

 larvae of Littorina), and very small shell cockles (not 

 larvae) may be found, and, indeed, the fish appear to take 

 whatever organisms are most abundant, and easily 

 captured. Copepods, however, seem to be the main food 

 of the smallest demersal stages of plaice, and other 

 Pleuronectids, in most parts of the Lancashire District. 



(c) The Horse Channel Grounds. 



These include the offshore part of the Mersey Estuary 

 extending from about the Liverpool Bar Light Vessel, 

 along the outer edge of the Banks into Horse Channel 

 proper, and then over towards the entrance to the Estuary 

 of the Dee. The catches made on these grounds have all 

 been summarised in Table XVIII, but those catches made 

 in Rock Channel and in Crosby, Formby, or Queen's 

 Channels are not so included. These latter grounds 

 harbour smaller plaice than are found more offshore. 



The fish caught here resemble, in their range of 

 lengths, those caught on the Nelson Buoy grounds. 

 Their lengths may be summarised as follows: — 



