In order to endeavour to co-ordinate the work of the many naturalists who make use of the tow-net round the coasts of the British Isles during the year, the following circular has been issued. The list of organisms, upon the presence or absence of which information is desired, contains only such as can be quite easily recognised. The scheme must be regarded as more or less experimental for this year, with a view to finding out what can be done in this direction.