90 BRITISH TUNICATA. 



Ovaries forming a linear series on eacli side, with 

 spermatics (?) or liver (?) between. 



Lengtli half to three quarters of an inch; breadth 

 one third less. 



Hab. On shells and stones, from about 15 to 25 

 fathoms. 



ENGLAND. Lul worth Cove, Dorset (Jeffreys) . [Devon 

 (Forbes). Falmouth ; in trawl refuse (Cocks, 184'.)) ; 

 and] Mount's Bay (Forbes $' McAndrew) ; Cornwall. 



SCOTLAND. Hebrides (Jeffreys Sf Norman). 



CHANNEL ISLANDS. Guernsey; dredged (Norman). 

 Near Castle Cornet, Guernsey (Alder). 



First record. - - Forbes, 1848 ; coll. Forbes & 

 McAndrew, 1846. 



In form this species resembles a Patella, or is 

 somewhat doridiform. The test (PI. XXX, fig. 8) is 

 firm, hard, and coriaceous, moderately thick and 

 convex above ; flat, colourless, soft, and comparatively 

 thin at the under or attached side, with the marginal 

 border expanded ; the inner surface shines with a 

 metallic lustre. 



The mantle (PI. XXXII, figs. 6 and 7) is thick and 

 fleshy, and is attached throughout, but is usually found 

 detached in spirit specimens, though never shrunk up 

 as in the Ascidise ; on the contrary it completely fills 

 the interior of the cavity, hence it is evident that the 

 separation took place after death from the influence of 

 the spirit. The muscular fibres are a little separated 

 and are regularly arranged. At the base or attached 

 side they are comparatively feeble, and seem mostly 

 disposed in a radiating manner ; above they are stout 

 and radiate from the orifices, and are crossed by 

 numerous minute fibres. A few angular pallial nodules 

 are situated in the vicinity of the endostyle. 



The branchial sac (PL XXXIII, fig. 6) is very 

 delicate and has four folds at each side ; the anterior 

 pair is short, the posterior narrow. The primary 

 vessels are irregular in size and have frequently a 



