228 Proceedings of the Royal Physical Society. 



5 fathoms ; and have collected it between 

 tide marks at several points on both 

 shores of the Firth. 

 Pelonaia corrugata (Forb. and Goods.). 



This species was dredged by Professor 

 Goodsir in deep water off Anstruther, and 

 was described first in Jameson's Edinhurgh 

 New Philosophiccd Journcd for 1841 (vol. 

 xxxi., p. 29). The only occasion, so far as 

 we are aware, on which it has since been 

 taken in the Firth of Forth was in 1872, 

 when it was dredged by the German 

 North Sea Expedition in 24 fathoms, off 

 the Bass Eock.* Dr M'Intosh informs 

 us that he has obtained this species 

 several times at St Andrews. It has 

 also been found in Berwick Bay and 

 down the Northumberland coast. 



ASCIDIID^. 



Ascidia virginea (0. F. Muller). 



This species, which is synonymous with 

 Ascidia sordida (Aid. and Han.), is very 

 common in a few fathoms of water and 

 upwards in all parts of the Firth, 

 On the oyster banks it occurs in profu- 

 sion adhering to dead shells, Algee, Zoo- 

 phytes, etc. The specimens are of large 

 size, and often united in clumps. We 

 have also dredged it plentifully in other 

 parts of the Firth, viz., north-east of Inch- 

 keith, 12 fathoms; Aberlady Bay, 9 

 fathoms ; off the Isle of May, 8 fathoms ; 

 and off Fidra, 7 fathoms. 

 Young specimens of this species are often 

 obtained adhering in clusters to masses of 

 Gemellctria loricata, and in this condition 

 are frequently found on the beach after 



* Kupffer — Jahresb., VIT. Tiinicata, p. 227. 



