In connection with the work of the Plymouth Laboratory it has been the custom of the Marine Biological Association for several years past to extend its operations during the summer months to the various harbours on the coast of Devon and Cornwall, with a view to making a comparative study of the faunas found in the different localities and of correlating, so far as that may be possible, differences in the character of the fauna with differences in the physical conditions prevailing in each. In former years this has been done by making occasional visits, lasting generally for a few days only, in our small steamer, the Busy Bee. It was found, however, that if investigations of this character were to be satisfactorily carried out some arrangement would have to be made for remaining in one locality for longer periods, and working each harbour in turn in more detail. Mr. J. W. Woodall kindly came to our assistance and purchased the hull of an old cruising yacht, which he caused to be fitted as a small floating laboratory and house-boat, and placed at our disposal for use in connection with the researches. This vessel, the Dawn, which can be towed by our own steamer, has been stationed at Salcombe during the present summer and has proved herself to be very well adapted to the work for which she was intended. We have also to thank Mr. Woodall for defraying the expenses of keeping the Dawn at Salcombe.

Having attempted to investigate the Polychæte fauna of the Plymouth district during those favourable opportunities which have occurred during the past three years, I now put upon record some few notes respecting a small section of this interesting but extremely perplexing group.

Until the spring of 1899 the true or common octopus (Octopus vulgaris, L.) had been comparatively rare in the neighbourhood of Plymouth during the past ten or twelve years—i.e. since the opening of the Plymouth Laboratory in 1888. Specimens could only be obtained for the aquarium at long intervals, in spite of the tempting inducements offered to fishermen. As much as ten shillings has more than once been given to fishermen for a specimen of this voracious mollusk. On the other hand, the smaller and less powerful octopod known as Eledone cirrosa was almost always obtainable, and the octopus tank in the aquarium was rarely devoid of several specimens.

In the early part of last year (1899) the situation began to change, and we were for the first time able to keep the tank supplied with a number of true octopus, since which date there has been no difficulty in procuring an unlimited number of specimens, either from the professional fishermen or in the ordinary course of our own fishing operations.

We noticed this increase in the abundance of octopus before there was any means of judging whether it was a purely local phenomenon, or was observable over a wider area. The first specimens were brought to us in January, and from May onwards they were obtained in increasing abundance. Early in the same year, however (though I have no exact record of the date), a visitor from the Channel Islands informed me that the increase of octopus in those islands was so great as to have already caused much damage to the shell fisheries there, since the octopus entered the pots of the fishermen, and destroyed the crabs and lobsters which had been caught.