OP NORTIIUMRERLAND AND DURHAM. 105 



terminal slightly tubular, tuberculated or echinated, and divided 

 at the top into six pointed segments. Anal aperture about one- 

 third down the body on the upper side, sub-tubular, slightly 

 tuberculated and divided into four segments, shorter than those 

 of the branchial aperture. Length three-eighths of an inch. 



On the under side of stones between tide-marks, Cullercoats 

 and Whitley, not common. 



125. ASCIDIA, LinncEus. 

 * Cylindrical or rounded, and partially attached. 



1. A. iNTESTiNALis, Linn. 



Ascidia intestinalis, Forb. and Hani. Brit. Moll. i. 31. 

 Not uncommon between tide-marks ; laterally attached to 

 stones at its posterior extremity. It inhabits various depths, 

 and is occasionally brought in on the fishing lines. Those from 

 deep water are larger than the shore variety, and of a greenish 

 yellow colour. This species is flaccid, when out of water, and 

 very contractile. 



2. A. soRDiDA, Aid. and Eanc. 



Body ovate, of a dull semi-transparent yellowish white, nearly 

 smooth, but coarse and with an uneven surface ; attached by a 

 narrow base. Apertures terminal and not far apart, papillose or 

 very slightly tubular, more or less echinated or tuberculated ; 

 the branchial aperture eight-cleft, the anal six-cleft, with a red 

 eye-spot at the base of each division. Outer tunic transparent, 

 vitreous, and colourless, rather tough, with very little power of 

 contraction or expansion. Inner tunic about one-third less than 

 the outer one, soft, yellowish, and generally very much blotched 

 and spotted with crimson, towards the upper end. Branchial 

 sac, with small even reticulations a little thickened at the inter- 

 sections. Circle of tentacular filaments simple and slender. 

 Length about two inches ; breadth an inch and a quarter ; but 

 very variable in size. 



This is one of the commonest Ascidice brought in on the fish- 

 ing lines at Cullercoats. It is usually attached to corallines ; 

 occasionally to shells and other substances. In its young state 

 it is gregarious, and is found in clusters on Gemellaria loricidata, 



