464 Scientific Proceedings, Royal Dublin Society. 



LEMON DAB — Pleuronectes microcephalus. 



During the SurTey, the stomachs and intestines of 60 Lemon Dabs were examined. 

 5 were empty. In 9 the nature of the food was indistinguishable. Of the remaining 

 46, EcMnoderms, Brittle Stars {0. albida) occurred in 1 ; Annelids in 36, 78 per cent. ; 

 Sabella in 2 ; Nereis in 1 ; unidentified Annelids in 33 ; Gephyreans in 2 ; Crustaceans 

 in 5 ; Spider crabs {Stenorhynchus) in 1 ; unidentified Crustaceans in 4 ; Lamelli- 

 branchs in 2 ; Gastropods, Philine aperta in 1 ; Fish, Goby, in 1. 



It appears, therefore, that whilst other groups of invertebrates and fish contribute 

 an insignificant proportion, the bulk of the food is derived from Annelids. According 

 to Smith the same appears to be the case in the Firth of Forth and St. Andrew's Bay. 

 That observer notices that the relative proportions of some of the less important groups 

 change with the change of locality. He records Sea Anemones from the stomachs of 

 two examples. 



POLE DAB — Pleuronectes cynoglossus. 



In 1890 the stomachs and intestines of 27 were examined. Annelids occurred in 

 most. Crustaceans, Gammarids, Prawns {Falcsmon) and Crabs in a good many. 



In 1891 21 were examined. In 6 the nature of the food was indistinguishable. 

 Of the remaining 15, Echinoderms, Brittle Stars {Amphiura) occurred in 6, 40 per 

 cent. ; Annelids in 12, 80 per cent. ; Crustaceans in 4, 26 per cent. ; Lamellibranchs 

 [Tellina) in 1. 



Thus it appears that the Pole Dab derives most of its food from Annelids, Echino- 

 derms, and Crustaceans. As this fish has the greatest known vertical range of any 

 British flat fish, it follows that its diet must be regulated by the invertebrate fauna of 

 the depth at which it happens to be. In the comparatively shallow water (about 30 

 fathoms) from which the specimens which we examined came, it appears to exhibit an 

 absolute preference for Amphiura amongst Echinoderms. As to the other groups our 

 identification is insufficient to help us. 



Smith found that ' ' in the Firth of Forth these fish feed very largely, if not 

 almost exclusively, on Annelids (especially Sabella) . . while Echinoderms and Fish 

 are foimd on very rare occasions." Our observations, numerically rather less, show a. 

 greater frequency of Echinoderms. 



PLAICE — Pleuronectes platessa. 



During May, June and July, 1890, the alimentary viscera of 267 Plaice were 

 examined. The Records do not show the exact numbers in which each sort of food 

 occurred. It appears, however, that while a number were empty. Annelids and 

 Lamellibranchs constituted the greater part of the food. Echinoderms contributed the 

 next considerable quotum : then Crustaceans, whilst Fish and Gastropods furnished 

 equally small proportions. Actinians, Polyzoans and Ascidians complete the list, each 

 with a single occurrence. 



In the different groups the identified forms had the following order of frequency: — 

 Actinians. Edtvardsia. Echinoderms. (1) Brittle stars, including Amphiura 

 Jiliformis and. Ophioglypha lacertosa. (2) Spatangus and Synapta (once each). Annelids 



(1) Nereis and Nephthys (2) ; Lugworm {Arenicola), Zagis, Lanice, Scale-back {Ear- 

 mothoe) and Sea Mouse {Aphrodite). Crustaceans (1) Spider crab {Stenorhynchus); 



(2) Shrimps, Schizopods, Amphipods, Hermits and Shore Crabs. Lamellibranchs (1) 

 Razor Shells (mostly ;S. ensis) ; (2) Venus gallina and Nucula nucleus ; (3) JJonax 

 anatinus, Tapes and Tellina ; (4) Mactra solida, Pecten and Psaimnobia. Siphons 



