Mollusks. 5707 



their studies. Most beautiful the Tunicata certainly are ; for although 

 the most common species of the Ascidia?, A. men tula, is not very attrac- 

 tive in its appearance, many of the rarer Ascidise are lovely, and all 

 the Botryllidae are most exquisite objects when alive. I wish the fol- 

 lowing list to be looked upon rather as a skeleton of what may 

 be done in the Firth of Clyde than as a perfect catalogue : a 

 diligent collector might very greatly add to the number of species. 

 1 was so much taken up with other branches that I was unable 

 to attend to the Tunicata as I should have wished. I saw many more 

 species than those mentioned, but was obliged for want of time 

 to leave them unexamined : this remark applies especially to the 

 genera Leptoclinum, Botryllus and Botrylloides. 



Fam. I. Botryllidce. 



Leptoclinum gelatinosum is to be found on Fuci and Laminariae, at 

 low water-mark/ round the shores of the Isle of Cumbrae. 



Diastoma variolosum. The Allans and other parts of Cumbrae, on 

 Fuci in rock-pools, but not common. 



Botryllus Schlosseri. This beautiful species is frequent "on stones 

 and sea-weeds," at low water-mark, in those parts of the Clyde I have 

 examined. 



Botrylloides Leachii. Parasitic on Laminaria digitata, spring tide, 

 the Allans. 



Fam. II. Clavelinidae. 



Clavelina lepadiformis. Forbes and Hanley give Lamlash and 

 Rothesay Bays as localities for this species, on the authority of 

 Mr. Alder. 



Fam. III. AscidiadcB. 



Ascidia intestinalis. This pellucid green species is common on 

 dead Pectens, Cyprinae, and other shells in the Coralline Zone : it is 

 generally found on the inside of the valves. 



„ venosa. I procured one specimen of this lovely Ascidia 

 between Cumbrae and Bute, in fifteen fathoms water. 



„ mentula. Frequent off Cumbrae, and in Lamlash Bays. 

 From one specimen I extracted no less than eleven Crenella marmo- 

 rata, some of them of large size, such as are not to be found else- 

 where than on the west coast of Scotland. 



„ arachnoidea. Lamlash, Alder, Forbes 8$ Hanley. 



