94 Mr. Thompson on the Mollusca of Ireland. 



' Obtained by dredging in the loughs of Strangford and 

 Belfast ; first distinguished as an Irish species by Dr. J. L. 

 Drummond. It is remarked by MuUer to be common about 

 Christiansand. 



Ascidia pnmum, Mull. Z. D. vol. i. p. 42. tab. 34. fig. 1 — 3. 



Procured in the same localities as last. 

 *Ascidia aspersa, Mull. Z. D. vol. ii. p. 32. tab. 65. fig. 2. 



As last. 



* Ascidia scabra, Mull. Z. D. vol. ii. p. 33. tab. 65. fig. 3. 

 As last. Possibly not distinct from it. 



Ascidia rustica, Linn. Mull. Z. D. vol. i. p. 14. tab. 15. 



Commonly investing the larger marine plants — found on 

 shells, stones, &c. This species is much less common on our 

 shores in the adult than in the young state, when assuming a 

 flattish oval form, and coloured like red cornelian, it is seen 

 beautifully studding our larger Fuci. 



Lamarck strangely considered that the A. scabra, Mull. 

 might be identical with this — they certainly have no relation 

 to each other. Nor can I believe with him that the A. patula 

 and A. aspersa, Mull, have any connexion with A. rustica. 

 Anim. sans Vert. t. 3. p. 123. 



^Ascidia parallelogramma, Mull. Z. D. vol. ii. p. 1 1 . tab. 49. 



I have taken this beautiful species (which is admirably re- 

 presented in the work just cited,) on different occasions when 

 dredging in Strangford lough ; it was attached to Algae. 



Ascidia echinata, Linn. Mull. Z. D. vol. iv. p. 10. tab. 130. 



fig. 1. 



Of this well-marked and pretty species, I obtained an in- 

 dividual parasitic on one of the larger Ascidia dredged in 

 Strangford lough. 



^Ascidia orbicularis, Mull. Z. D. vol. ii. p. 53. tab. 79. f. 1,2. 

 Obtained on Zostera marina in Strangford lough. 



^Ascidia mammillaris, Delle Chiaie, vol. iii. p. 187, 197- 

 tav. 45. fig. 14. 



Found attached to Laminaria digitata, &c. in Belfast and 

 Strangford loughs. The spinous tubercles in my specimens 



