ANI.t THE HEBRIDEAN DIAZONA VIOLACEA. 165 



surface — and one wondered how many still finer specimens had dropped off 

 in coming up through the water. 



I can agree with the Marshalls' remark : '' Not only is the geographical 

 •distribution of Funicidina a very limited one, but wherever it does occur it 

 seems to be confined to a very small spot, in which it occurs fairlj- abun- 

 dantly " — although I do not doubt that other localities will yet be discovered 

 on the west coast of Scotland containing virgin forests of this largest and 

 ^stateliest of the British Coelenterata. 



(2) DiAZONA VIOLACEA, Savigny. 



This well-known Mediterranean Tunicate was described and figured by 

 Savigny in 1816, and the genus Diazona was placed by him in the " Tethyes 

 •composees," immediately after Clavelina : both in description and figure 

 the colour is given as a beautiful violet. Other notable characters in the 

 original description are : the branchial and atrial apertures both 6-raved, 

 the internal longitudinal bars of the branchial sac provided with papilla?, and 

 the meshes of the branchial sac containing each four stigmata. As we shall 

 see, the latter two characters require some qualification. The first British 

 specimen was found over sixty years ago by Edward Forbes and John Goodsir, 

 in 30 fathoms of water, off" the Croulin Islands, near Skye, and was described 

 by them as a new genus and species under the name SijntefJiys liehridicus in 

 the ' Transactions of the lioyal Society of Edinburgh ' for 1851 (vol. xx. 

 p. 307). In this paper, Forbes and Goodsir tell how they were at the time 

 on a yachting cruise " with our indefatigable friend Mr. McAndrew * 

 .among the Hebrides, in the month of August, 1850 "" ; and in describino- their 

 discoveries they go on to say — " the most remarkable of them is the laro-est 

 of Compound Ascidians yet discovered in the Atlantic. Its nearest described 

 ally is the genus Diazona of Savigny, between which animal and Clavelina 

 it constitutes a link ; one of considerable zoological importance " — and more 

 to the same effect, showing that Forbes and Goodsir had compared " Syn- 

 tetliys"" with Diazona and regarded it as generically distinct. They point 

 out that their "rem-arkable animal'' is of an apple-green hue, that the 

 branchial and atrial apertures are not lobed (although the atrial has six white 

 •ocelli), that the ascidiozooids have a sessile abdomen and are marked by lines 

 of white pigment, that the branchial sac has 13 rows of stigmata, hooked 

 fleshy tubercles at the angles of the meshes, and only one of the stigmata 

 in each mesh. Forbes and Goodsir give a coloured figure of their colony, 

 from which my fig. 2, on PI. 13, is copied, to give some idea of the dis- 

 tinctly green colour of the living animal. It is, however, in this figure, 



* Mr. Robert McAndrew was a Liverpool merchant who owned tlie yacht 'Naiad/ a 

 .70-ton yawl, which he made good scientific use of on dredging expeditions, chiefly in the 

 interests of conchology. 



15* 



