470 Scientific Proceedings, Royal Dublin Society. 



of Gapers {My a) in 1 ; unidentified Siphons in 2 ; unidentified LamellibrancLs in 5 ; 

 Cephalopods {Eledone), in 1, 1 per cent. ; Fisli in 11, 20 per cent. ; Sand-eels in 3 ; 

 Crystallogobius in 2 ; Cepola and young Herrings or Sprats, each in 1 ; unidentified 

 fish in 4. 



It thus appears that the Thornback lives on a very varied diet, chiefly of Crusta- 

 ceans (especially Swimming Crabs, Angular Crabs, Common Shrimps, Mask Crabs, 

 and Hermits), and to a less and seemingly variable extent on fish. Annelids (chiefly 

 Sea Mice) and Lamellibranchs are subsidiary articles of diet. Cephalopods and Echi- 

 noderms are rarely eaten . Gastropods are perhaps only represented by shells, the 

 " houses" of Hermits. 



SPOTTED EAT— -Raia maciilata. 



During May, June, and July, 1890, 72 stomachs were examined. The exact dis- 

 tribution of the food cannot be gathered from the Records. It appears, however, that 

 the majority contained Fish, chiefly Sandeels, with a few Sprats and Herring and 

 unidentified forms. A much less number contained Crustaceans, including Norway 

 Lobsters {Nephrops), Hermits, Crabs, Schizopods, Common Shrimps, Amphipods, and 

 Isopods. Lamellibranchs, chiefly the Siphons of Mya, were about equally numerous 

 with the last. 



During the rest of the Survey, 36 stomachs were examined. 10 were empty, and 

 2 contained indistinguishable matter. Of the remaining 24, Annelids occurred in 1. 

 Crustaceans in 7, 29 per cent. ; Swimming Crabs in 3 ; Common Shrimps in 2 ; Mask 

 Crabs {Corystes), Gonopkix and Atelecyclus each in 1 ; Lamellibranchs, Razor Shells 

 {Solen) in 3, 12 per cent. ; Fish in 15, 62 per cent. ; Sand-eels in 13 ; Crystallogohins 

 in 1 ; unidentified fish in I . 



It appears, therefore, that the diet of this Ray is less indiscriminate than that of the 

 Thornback. Unlike the latter, the Spotted Ray feeds chiefiy on fish, especially 

 Sandeels, whilst Crustaceans, including much the same forms as the Thornback, form 

 a less important article of diet. Lamellibranchs (Razor Shells) contribute very little, 

 and Annelids hardly at all. 



SANDY RAY — FMia circularis. 



Of 2 stomachs examined, 1 was empty. The other, that of a large example from 

 deep water (154 fathoms), contained the remains of a fair sized Picked Dog. 



By taking the above observations in the inverse order we are better able to form 

 an idea of the competition which exists for each kind of food. 



Actinians. Edwardsia and Cerianthus occurred each on one occasion in a Plaice's 

 stomach. Feachia once in the stomach of a Small-spotted Dog. Edwardsia, however, 

 appears to be sometimes much eaten by the Common Dab on the Scotch Coast. 



Hydroids. Ocasionally eaten by the Common Dab. 



Echinoderms. The chief food of the Piper, Haddock and Common Dab, Largely 

 eaten by the Long Rough Dab, Plaice, Lemon Dab, Pole Dab and Common Sole. 

 Occasionally by the Cod, Whiting, Hake, Small-spotted Dog and Grey Skate. Rarely 

 by the Thornback. 



Annelids. The chief food of the Lemon Dab, Pole Dab, and Common Sole. 

 Largely eaten by the Haddock, Plaice and Small-spotted Dog. Moderately by the 

 Common Dab. Occasionally by the Sapphirine Gurnard, Grey Gurnard, Cod, PoUack, 

 Long Rough Dab, Turbot, Witch and Thornback. Rarely by the Spotted Ray. 



