56 THE INVERTEBRATE FAUNA 



storms; they are probably what are referred 

 to by Dr M'Bain as Ascidia prunum. 

 These young specimens are perfectly trans- 

 parent, and have a beautiful crystalline 

 appearance. They are excellent objects 

 in which to study the circulation in the 

 living animal. 



Ascidia depressa (Alder). 



We obtained several specimens of this 

 characteristic species, some years ago, at 

 low water mark near Elie. 



A. scabm (0. F. Muller). 



This species we also obtained on the same 

 occasion, near Elie, in considerable 

 quantity. 



Ciona intestinalis (Linnaeus). 



This beautiful species is fairly common on 

 the oyster bank, and on muddy bottoms 

 elsewhere throughout the Firth ; it attains 

 a large size. We have dredged it in 

 various parts of the Firth, and have also 

 taken it at low water mark at Elie and 

 Aberdour, generally adhering to the roots 

 of Laminaria. 



ASCIDLE COMPOSITE. 



BOTRYLLID^E. 



Botryllus scklosseri (Pallas). 



This species is common at low water mark 



on the shores of the Firth. It is usually 



found on the under surface of large stones, 



or encrusting the roots and sterns of 



Laminaria, Fucus, etc. 



W^e have taken it at Elie, North Berwick, 



Aberdour, and other localities. 



Dr M'Bain records this species in his list. 



R polycyclus (Savigny). 



This species appears to be rarer than the last. 



