CORELLA PARALLELOGBAMMA. 27 



long and slender. Branchial she (fig. 30) with the 

 secondary vessels arranged in spirals of five or six 

 coils each ; papillary membranes ample, with the free 

 border considerably thickened, but scarcely produced 

 into tentacular points. Oral filaments numerous, 

 rather stout and pointed. 



Height one to two inches ; breadth about one third 

 less. 



Hab. [Adhering to dead shells, Alga?, &c.,] at 

 low water-mark and in deepish water. 



On most parts of our coasts, but apparently rare in 

 the south. 



ENGLAND. Coast of Durham and Northumberland 

 (Alder; Hodge). [Dogger Bank (Alder). Brighton, 

 Sussex (Merrifield, 1860). Grwyllyn-vase, Swanpool, 

 Pennance, etc., Falmouth, Cornwall (Cocks, 1849). 

 Scilly Isles (Cants, 1850).] Isle of Man (Forbes; 

 Alder). 



WALES.- -Tenby, Pembroke, at low water-mark 

 (Gosse). 



SCOTLAND. - - Aberdeen, abundant (Macgillivray). 

 Firth of Clyde (Norman; Carpenter). Hebrides 

 (Forbes fy Me Andrew). [Arran (Land sboro ugh, 1847).] 

 Shetland (Forbes fy McAndrew); [10 miles east of Balta 

 (Norman, 1868)]. 



IRELAND. Strangford Lough, Down, and Bound- 

 stone Bay, Connemara, Galway (Thompson). 



First record. [Thompson, 1840.] 



This species is remarkable for its subquadrate form 

 and the brilliancy of the pallial colouring ; and it 

 differs likewise from the other species of the genus 

 in many points of detail. 



After much investigation we have come to the con- 

 clusion that the Ascidia virginea of British authors is 

 only a brightly-coloured variety of Corella parallelo- 

 gramina of Miiller, and that the true A. virginea of 

 that author has yet to be discovered, at least on the 

 British coast, if indeed it be at all known to modern 



