250 REPOET 1868. 



save in this one instance, comparatively uncommon. Near the same spot 

 Antedon Sarsii was brought up in thousands, yet, except in that one day's 

 dredging, I never was fortunate enough to meet with the species. In this 

 same neighbourhood Ophiura Sarsii was found very abundantly, but it was 

 scarcely ever seen again during these dredgings. Cidaris papillata and 

 Spatangus meridionalis appeared to be confined to one limited area to the 

 north of Unst, yet there they were to be met with in considerable numbers. 

 Similarly Tealia digitata was chiefly found in one particular spot; and 

 the same is true of Ascidia obliqua, A. sordida, EscJiara lorea and Icevis, 

 Gellepora attenuata, Tessarodoma gracile, Pcdmicellaria elegans, Hornera bo- 

 realis and violacea, Zoanthus papillosus, Sidisia Barleeii, Pennatula phos- 

 pJiorea, Tubularia attenuata, Quasillina brevis, Phakellia robusta, Isodictya 

 firtibriata, Oceanapia Jeffreysii, &c., all of which, though dredged occasion- 

 ally elsewhere, were chiefly to be found in one circumscribed area, where 

 they appeared to be very common, and in some instances to live in the most 

 astounding quantities. When cases of remarkable local distribution occur in 

 channels or bays the circumstance is not unexpected, but it is different when 

 we are dredging in the wide expanse of the Atlantic with apparently no 

 causes at work to make such differences in the nature of the sea-bottom, 

 which around Shetland is in general of nearly uniform though gradually 

 increasing depth, as would render different positions peculiarly fitted for the 

 life of different species. Yet this would seem in a most marked degree to 

 be the case. The nature of the sea-bed on the Haaf is continually changing, 

 and the character of the inhabitants varies with it. At one moment the 

 dredge is scraping over hard stony ground calculated to tear the nets to 

 pieces, at the next it is sunk deep in fine sand or in an unctuous mud. 

 When the dredge is hauled up it will be often found that while down it has 

 at first travelled over a soft bottom and thence brought up in the sand some 

 extremely interesting species, perhaps in profusion, while subsequently it has 

 been dragged over hard ground and the stones which it has thence collected 

 have crushed to pieces the delicate organisms which lay below them in the 

 net. We at once tack and endeavour again to strike the spot where we had 

 first let down the dredge no easy matter certainly in the open sea, where no 

 bearings can be taken from the land; the whole day is spent, perhaps many 

 days are spent, in the search for that spot, but Ulocyafhus arcticus or Trochus 

 amabilis declines again to show us its pretty face. 



It may be well to mention that the term " Haaf," which constantly occurs 

 in this Report, means the open sea, and the Shetland fishermen, more espe- 

 cially those of the " Out " or " Whalsey Skerries," speak of the " inner," 

 " middle," or " outer Haaf," according to the distance of the fishing-ground 

 from land. The " outer Haaf-"' to the east of the Whalsey Skerries is about 

 forty miles from those rocky islets, and fifty-five or sixty miles from the 

 mainland. 



In the catalogue of species which follows in this Report I have, in the case 

 of those animals which have only occurred once, generally appended the date 

 of the year in which they were discovered. The following account of the 

 naturalists who accompanied the expeditions in the different years will enable 

 the reader to assign the credit of each discovery to the right persons. Many 

 invertebrata which were preserved during the years when I was not myself 

 present with the Committee, and belong to the classes on which I report, 

 were kindly placed, in my hands by Mr. Jeffreys. In the notes which follow, 

 the specimens having been actually examined by myself, I hold myself 

 responsible for the correctness of the identification of the species in all cases, 

 except where the locality or note is contained within inverted commas, where 



