MARINE BIOLOGICAL STATION AT PORT ERIN. 75 



Ascidians and Radiata, some of them so curious in 

 themselves, and so important in their zoological bearings, 

 that we have thought it desirable to lay an account of 

 their characters and anatomy before the Royal Society 

 of Edinburgh. The most remarkable of them is the 

 largest of compound Ascidians yet discovered in the 

 Atlantic. Its nearest described ally is the genus Diazona 

 of Savigny, between which animal and Clavellina it 

 constitutes a link ; one of considerable zoological 



importance The discovery of a creature thus 



filling up a gap in the animal series was of itself a 

 sufficient harvest from our autumn tour ; in this instance 

 our pleasure was enhanced by the beauty and singularity, 

 as well as novelty, of the remarkable animal we have first 

 to describe. 



" The Syntethts, for so we propose to designate the 

 Ascidian, presents itself in the form of a compact 

 gelatinous mass of half a foot, and sometimes more in 

 diameter, and very nearly an equal height. It is affixed 

 to the rock or stone by a short, slightly spreading base 

 of various breadth, whence rises as an inverted pyramid 

 the body of the mass, irregularly circular and slightly 

 lobed, spreading out at its summit. It is of a translucent 

 apple-green hue; the surface is nearly smooth. The whole 

 of the expanded disk is thickly studded with individual 

 ascidians growing out, as it were, from the common mass. 

 They are arranged in irregular rows, with a tendency to 

 concentric order. Each individual measures, when full 

 grown, nearly two inches in length, and has the shape of 

 an elongated ampulla, with two terminal orifices, set 

 well apart, but not very prominent, and nearly on the 

 same level. The outer tunic is a smooth and transparent 

 softly cartilaginous sac of a pale emerald green tint, 

 slightly swelling out above the centre, and contracted, 



