PLATE CXXXIX. 



ceth in Caernarvonshire, and near Yarmouth. We have seen it on 

 other parts of the sea coast of North Wales, and in equal plenty 

 on those of South Wales likewise. On the coast of Dorsetshire, 

 according to Dr. Pultney, fragments are found very frequently, but 

 none very perfect. In the History of that County the following ac- 

 count is given of it. — " Gregarious Sabella. This is composed 

 of a mass of fine sand, and particles of broken and finely comminuted 

 shells, aggregated by vermiform animals of the Nereis genus, each, 

 lodged in its separate tube close to, but not interfering with each 

 other. All the tubes end in orifices on the upper or the same surface. 

 I but once saw a mass of this kind, about the size of a large apple, on 

 the beach, a mile east of Weymouth ; but I suspect it is not very un- 

 common, as fragments are very frequent." 



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