156 PI,VMOUTH MArJNE INVERTEBRATE FAUNA. 



paring a similar account of the fauna of the inshore grounds in the 

 neighbourhood of riyniouth. As the work proceeded, however, it was 

 realised that, owing to the great damage which has been caused to the 

 grounds within easy reach of the harbour by the constant discharge of 

 mud and refuse from barges working in connection witli the new dock- 

 yard extension at Devonport and other harbour works, any attempt to 

 prepare' a consecutive account of the fauna and bottom-deposits over 

 the whole area, such as was given for the grounds from Eddystone to 

 Start, would be a matter of extreme difficulty and of little use. 



The present report has therefore been arranged in a somewhat 

 dilTerent way. A general account is first given of certain typical 

 areas, their physical conditions are briefly described, and a short list 

 is added of the more common and characteristic species which are 

 found in them. This description of the grounds is followed by a 

 general list of the species which have been recorded in the whole area 

 investigated, and the local distribution of each, so far as it is shown 

 from the Laboratory records, is given. The information supplied in 

 the two sections of the report when combined furnishes for each species 

 a general idea of the conditions under which it lives. 



Some explanation is necessary as to the scope of the general list. 

 It is not intended to be a complete list of all species which have been 

 recorded from the Plymouth district,* but only of such as have been 

 found in recent years as a result of the work carried on at the 

 Plymouth Laboratory and for which the exact locality of capture is 

 known. All records which appeared to be in any way questionable 

 have been deliberately omitted. Omissions, which in some groups 

 especially are known to be exceedingly numerous, are easily made 

 good at a later date, whilst false records are less readily corrected. 



In all cases the initials of the person or persons responsible for a 

 record have been given, but it must not be supposed that the persons 

 so indicated were the first or only ones to find the species in the locality 

 indicated. During the course of preparing this paper for the press it 

 has been frequently necessary, especially in the case of the conniion 

 and widely distributed species, to frame a general note expressing facts 

 which have for long been well known in the Laboratory, but in order to 

 fix responsibility such notes have been followed by the initials of the 

 person by whom they were framed. In editing the notes, care has been 

 taken that the collection of records for each species shall, as far as 

 possible, give a not incorrect indication of the abundance and distribution 

 of the species in the Plymouth district. 



* Kecords for Plymouth previous to 1888 are sinnniariscd by Heape, "Preliminary 

 Rojiort upon the Fauna and Flora of Plymouth Sound," Jonni. Mar. Biol. Assoc, 

 Old Series, ii. 



