120 BRITISH ITXK'ATA. 



Ascidia sordida ALDER and HANCOCK in Trans. Tyneside Nat. 

 Field Club, I [1848], p. 199; FORBES and HANLEY Brit. 

 Moll. II [1849], p. 372; [ALDER in Nat. Hist. Trans. 

 Northumb. and Durham, I (1865) p. 11 ; NOEMAN in Eep. 

 Brit, Assoc. 1868 (1869), p. 302]. 



Bud)/ longitudinally ovate, of a semi-transparent 

 yellowish white, generally blotched with red, nearly 

 smooth, but with an uneven surface, and rather rugose 

 towards the apertures; attached by a narrow base. 

 Apertures terminal and not far apart, slightly tubular, 

 more or less echinated or tuberculated ; ocelli small 

 and inconspicuous. Test (PL XI, fig. 6) transparent, 

 vitreous and colourless, with a few longitudinal wrin- 

 kles, rather tough, and very slightly contractile. 

 Mantle yellowish, usually blotched and spotted with 

 crimson on the upper part. Tentacular filaments 

 slender [, alternately large and small]. Branchial sue 

 with rather small papillre. Oral lamina smooth. 



Lenntli an inch and a half to two inches. 



Hfil>. In the Coralline zone, N.E. England, usually 

 attached to zoophytes [ ; in deep water, on dead shells, 

 N.E. Scotland; on sandy ground, Shetland]. 



ENULAXD. On the north-east coast. Cullercoats, 

 Northumb., plentiful. [Falmouth, Cornwall (CV/,-.s, 

 1849).] 



SCOTLAND. On the north-east coast. Firth of Forth 

 (Dah/ell). Aberdeen (Macgillivray). AYick, Caithness 

 (Peacli). Shetland (Norman & Jeffreys [; Me Andrew 

 & Forbes] ). [East of the Isle of 'Balta, Shetland 

 (Normiin, 18(58).] 



First record. -- Alder and Hancock, 1848 (Mac- 

 gillivray, 1843, as Ascidia prunum). 



The mantle (PI. XI, fig. 7, and PI. XII, fig. 1) of A. 

 sordida is rather stout and is of a pale transparent 

 yellow colour, usually with scattered circular spots or 

 blotches of crimson towards the upper part ; and 

 freckled with opaque white, sometimes thickly accu- 

 mulated so as almost to obscure the alimentary tube, 



