52 



MARINE FAUNA OF ST. ANDREWS. 



these forms by him and the late Mr. Hancock (one of the 

 best minute anatomists this country has produced) will soon 

 be published. The most abundant simple form is the Ascidia 

 sordida of Alder and Hancock, which is thrown by storms 

 on the West Sands in large numbers, attached to sea- 

 weeds, sticks, shells, and other objects. A. mtestinalis is also 

 procured in this manner as well as between tide-marks ; 

 Pelonaia corrugata and Molgida arenosa, A. & H., affect deep 

 water only, and rarely occur during storms. The compound 

 forms are common under stones between tide-marks and in 

 the laminarian region : but much yet remains to be done in 

 this respect at St. Andrews. Though Ascidians on the ex- 

 posed parts of the east coast of Scotland are for the most part 

 rare in the laminarian region and between tide-marks, they 

 are common in still muddy waters on the west coast and in the 

 Hebrides, and in water which cannot but be slightly brackish, 

 as at the head of Loch Portan near Lochmaddy, where they 

 are both abundant and large ; they are also numerous and 

 large between tide-marks at Herm and in the rich waters 

 around the Channel Islands, as well as in the Zetlandic 

 voes. 



Cynthia echinata, L. (From the Minch.) 



