328 REPORT— 1864. 



Isocardia cor, Natlca monilifera, N. sordida, and Defrancia gracilis occurred 

 in a living state. These have been usually regarded as southern forms ; and 

 the last two are not in Loven's Catalogue. All are conspicuous and well- 

 known species ; and I havj selected them from many others in the same 

 category to show the wide range of their distribution. The first (^Isocardia 

 cor) is not uncommon in the newer glacial deposits near Christiania, and is 

 associated, with species some of which exist at present only within the arctic 

 circle. 



In one of my former Eeports I noticed that the marine fauna of Shetland 

 is in the main Scandinavian. This, indeed, would be the natural inference 

 from the geographical position of these isles. But it has undoubtedly also 

 a southern character, and includes many species which inhabit the Mediter- 

 ranean. Some naturalists, who appear not to have studied the question in 

 all its bearings, ascribe this southern element to the influence of the Gulf- 

 stream. I cannot help repeating what I have already urged elsewhere*, that 

 the eastern coasts of Shetland are, so far as can be ascertained, quite exempt 

 from the operation and effect of this mighty " river in the ocean." No seeds 

 of tropical plants, no lanthince, Sjjirula, exotic kinds of Teredo, Velella, or 

 other pelagic animals which usually accompany the course of the Gulf-stream 

 have ever bean found on any part of these coasts. The only driftwood which 

 has been observed floating in the sea, or cast ashore by the waves — and in 

 this treeless district every kind of wood is much sought after — consists of 

 Norwegian fir-trees, often with their roots, and drilled by the same species 

 of Teredo {T. megotara or nana) that attacks piles and fixed wood-work, as 

 well as boats, equally in the harbours of East Shetland and Norway. Besides, 

 another consideration must not be lost sight of, viz. that the Mediterranean 

 fauna is quite independent of the Gulf-stream ; and a glance at Maury's 

 chart will show that the direction of its course, or of the " drift " which 

 may have been mistaken for it, off the western coasts of Europe and 

 Africa (including the entrance to the Straits of Gibraltar) is entirely south- 

 ward, and forms in fact the return-current. The present distribution of 

 marine life in the European seas must be traced in some other way, and with 

 reference to geological conditions. Palaeontologists are well aware that many 

 kinds of Mollusca which stiU inhabit the Mediterranean, but not our seas, 

 left their remains on the area that now constitutes the eastern coasts of 

 England, perhaps at a period long antecedent to the origin of the GuK-stream. 

 Several species of Mollusca, which may be termed southern forms, likewise 

 occur on the Dogger Bank and the coasts of Yorkshire and Northumberland ; 

 and among them may be enumerated Trochus mlllegranus, t:<calaria Tvrtoni, 

 Natica sordida, Murex erinaceus, Defrancia brachiistoma, and Pleurotoma teres. 

 To these may be added a fine Echinoderra lately captured off Scarborough, 

 which had not before been observed so far north, viz. Echinus melo, var. Sar- 

 dica. It is not uncommon in the south of Europe ; but I believe it is only 

 known as British through Mr. Peach having discovered it, some years ago, on 

 the Cornish coast. 



Other branches of marine zoologj^, in connexion with the Shetland dredg- 

 ings, have been worked out by skilful and experienced naturalists ; and when 

 I mention their names and the departments which they have undertaken, the 

 members of the Association wiU doubtless be satisfied thnt full justice has 

 been done to these explorations. Heports or lists wiU be presented by Mr. 

 Aider as to the Nudibranchs, Tunicata, and Polyzoa, by Mr. Spence Bate 

 and the Rev. A. M. Norman on the Crustacea, by Dr. Baird on the Annelids, 



* ' Britisb Conchology,' Introduction, p. xeviii. 



