PLYMOUTH AND THE ENGLISH CHANNEL. 219 



importance. In dividing the genus Harmothoe into three sections, I 

 have relied largely upon the accuracy of Mcintosh's drawings. 



In the following synopsis the family and generic descriptions are 

 copied from Mcintosh (20), with a slight alteration of terminology and 

 omission of all points relating to internal anatomy. 



The local area included in the scope of this paper is the entire south 

 coast of Devon and Cornwall. The field thus defined is a large one, 

 and has not by any means been exhaustively worked. The central area 

 in the immediate vicinity of Plymouth is best known, and as the 

 operations of the Marine Biological Association extend east and west, 

 so the more likely and productive spots will be first visited, and the 

 intervening areas will receive attention in due course. The varied 

 character of the shores round Plymouth renders it a particularly rich 

 spot for Polychtetes. Extensive mud-flats occur in all the rivers, and 

 the shore in the Sound possesses numerous areas strewn with fucoid- 

 covered boulders and stones, with or without muddy sand, in large 

 patches. These form productive grounds for numerous species, the 

 richest and best of which are Drake's Island, Eum Bay, the Bridge, 

 and Bovisand Bay. 



Below tidal water Millbay Channel is, perhaps, the richest field. 

 The bottom there is covered with stones of varied character, rough and 

 smooth, usually bored by Saxicava and other boring animals. These 

 form the home of numerous hydroids, sponges, etc. 



Queen's Ground and Duke Eock are cleaner and yield irregular 

 clinkers from the ocean steamers, with shell detritus, all of which are 

 more or less covered with hydroids, polyzoa, and algie, etc. 



Outside the Sound, Wembury Bay is a favourite ground, and exhibits 

 every phase, from huge fucoid-covered boulders, stones, to muddy sand 

 and fine sand ; and though its area is not particularly large, its varied 

 character renders it exceptionally productive. 



The varied character of the bottom offshore has been indicated in a 

 remarkably precise manner by Allen, in his paper " On the Fauna and 

 Bottom-Deposits near the Thirty-Fathom Line from the Eddystone 

 Grounds to Start Point." 



The fauna of Salcombe Harbour has recently been investigated by 

 Mr. Allen and Mr. Todd with interesting results as regards Polychcetes, 

 and I am indebted to them for the opportunity of including those 

 species here, and further to the latter gentleman for giving me other 

 notes, which are distinguished by his initials. 



Throughout the paper I have marked with an asterisk (*) all those 

 species which are known to occur in the local area as already defined. 

 All those forms occurring elsewhere in the Channel are distinguished 

 by a dagger (f). 



