ASCIDIA. 33 



opaline, with a porcelain-like lustre, either milk-white, or marked 

 with reticulating lines, as if it were covered by a spider's web. 

 Branchial orifice terminal ; anal lateral and distinct ; both with 

 very strongly-marked lobes : ocelli inconspicuous. " Inner tunic 

 soft and dark blue." — (Mr. Alder.) 



Three inches in length. A very beautiful species. On the 

 south coast of England, Mr. Bowerbank. " Not uncommon on 

 the Cornish and Devonshire coasts. I have also found it at 

 Lamlash, Arran," Mr. Alder. [Taken in the Mgesna, E. F., 

 1842.] 



6. A. scABRA, O. F. Miiller. 



Zool. Dan. t. 65, f. 3. 

 Plate C, fig. 3. 



Body ovate, compressed, adhering by the side. Test tough, 

 white, transparent, scabrous, shewing the reddish branchial sac 

 shining through. Orifices sessile, approximate, near one extre- 

 mity. An inch to an inch and a half in length. 



Strangford and Belfast Loughs, W. Thompson. On fronds of 

 Laminaria in Killery Bay, west coast of Ireland, W. Thompson, 

 R. Ball, E. F. (1840). Irish Sea, not rare; west coast of Scot- 

 land, E. F. 



7. A. viRGiNEA, 0. F. Miiller. 



Zool. Dan. t. 49, f. 4.— A. opalina, Macgillivray, Mol. Ab. p. 312. 

 Plate C, fig. 2. 



Body irregularly tetragonal, compressed, adhering by base, and 

 sometimes partly by the side. Tunic smooth, glossy, crystalline, 

 firm, yellowish-hyaline. Through it the branchial sac, beautifully 

 marbled with crimson, and banded with white, is seen. Orifices 

 terminal, sessile, rather distant; ocelli red. Length and breadth 

 often two inches. 



" Ha3c frustam glaciei visu, tactu et ipso frigore refert, vix 

 ulli pulchritudine secunda." — MtfLLER. 



Dredged, adhering to dead shells, in twenty fathoms, four miles 

 from land, Ballaugh, Isle of Man, (1839,) E. F. Hebrides and 

 Zetland, R. M 'Andrew and E. F. Moray Firth, Captain Otter, 

 R.N. "Abundant in deep water off Aberdeen," Macgillivray. 



VOL. I. F 



