Mr. Gwyn Jeffreys on Dredging among the Hebrides. 387 



XLIX. — Report on Dredging among the Hebrides. 

 By J. Gwyn Jeffreys, F.R.S. 



[As this Report embodies important and recent papers by 

 Professors Sars and Jjoven, on the existence of animal life in 

 great depths of the sea, which do not appear to be known in 

 this country, I thought the subject would be sufficiently inter- 

 esting to publish it at once in this form, without waiting for the 

 appearance of the annual Report of the British Association for 

 the Advancement of Science. — J. G. J.] 



This exploration lasted nearly two months, viz. from the 24th 

 of May to the 14th of July in the present year. It comprised 

 Sleat Sound, Lochs Alsh, Duich, Slapin, and Scavaig, and the 

 Minch from Croulin Island to Loch Ewe. I had a good cutter 

 yacht, the master of which had been employed by me for many 

 years as dredger and took considerable interest in the work, an 

 active and willing crew, four serviceable dredges, 300 fathoms 

 of new rope, machinery for hauling up the dredges, a large tub, 

 sieves, and various other apparatus. The Hydrographer of the 

 Navy obligingly supplied me with such charts as I required, to 

 show the depths and nature of the sea-bottom in the district 

 which I proposed to examine ; and these were of great use in 

 dredging, as well as for navigation. The weather was too fine ; 

 we were often becalmed for many hours together : and instead 

 of steady breezes, we had too many of those squalls which are so 

 prevalent, and occasionally dangerous, in the Hebrides. 



The Hebridean seas have often been searched, but not explored, 

 by zoologists. Their great extent, and the number of lochs and 

 inlets which indent the coast in every direction, would render 

 necessary an immense deal of money, time, and patience for a 

 complete investigation. There is little probability that the 

 subject of the present Report will ever be exhausted. 



The invertebrate fauna of this district is of a northern charac- 

 ter, although there are a few exceptions. Such are, among the 

 MoUusca, Trochus umbilicatus, Phasianella pulla, Rissoa can- 

 cellata or crenulata, Odostomia lactea or Chemnitzia elegantissima, 

 and Pleurobranchus plumula. These may be regarded as south- 

 ern forms. The first and third occur as far north as Stornoway; 

 the second ranges to Dunnet Bay in Caithness ; of the fourth I 

 dredged a single specimen in the upper part of the Minch ; and 

 the last lives between tide-marks in the Isle of Mull. As a set- 

 off to the above, I would mention the following species, which 

 have now for the first time been found so far south as the 

 Hebrides, viz. Montacuta tumidula (a new species, which I will 

 presently describe), Trochus occidentalis, var. pura, Jejfreysia 

 globularis, and Odostomia eximia. The first is Swedish; the 



