146 Zoological Society ; — 



ence of the sun, and, in those regions, few coral-polypes carry on 

 their ceaseless work at a greater depth than 30 fathoms, thence 

 building upward to the lowest tide-mark. As we come towards more 

 temperate regions, the species diminish both in size and number ; 

 simple forms become proportionately more numerous, and their ba- 

 thymetrical range is greatly increased. 



The waters of north-western Europe might be expected generally 

 to be too much within the influence of Polar temperature to be fitted 

 for coral-life, even in its simplest form ; yet in our own seas, and 

 extending far into the Arctic Ocean, are found some few species 

 vying with the productions of the Tropics in brilliancy of colouring 

 and delicacy of structure. Here, however, we have a peculiar and 

 extraneous source of warmth in the Gulf Stream, whose waters, now 

 becoming widely diffused, but still retaining some portion of their 

 original excessive temperature and motion, exercise a sensible influ- 

 ence on the coast-productions of the western side of the British 

 islands. The course of the current in the neighbourhood of our 

 shores is marked sparingly, but distinctly, by the presence of eight or 

 ten species of living coral. 



The long list of habitats recorded by Mr. Gosse in his valuable 

 ' Actinologia Britannica' has been of great use to me in tracing the 

 range of our native species ; and although many parts of the coast 

 have been but little worked, enough has been done to furnish a 

 tolerably clear outline of the distribution of the coralligenous polypes. 

 From the writings of Maury and others, it appears that the Gulf 

 Stream is divided by the British Islands ; one portion going south- 

 ward to the Bay of Biscay, the other and main body of the current 

 sweeping away to the north by the Orkneys and Shetland. The 

 entrance of the English Channel and the Irish Sea would thus be 

 under the most direct influence of the warm current ; and it is in these 

 waters we find corals most abundant. Devonshire and Cornwall are 

 extremely rich in these productions ; and, including Weymouth Bay 

 (the only recognized locality for Hoplangia durotrix), the south- 

 western promontory of England can boast of five out of the eight 

 undoubted British species. They consist of two Caryophyllice, one 

 Sphenotrochus, Balanophyllia, and Hoplangia. Of these species, 

 Guernsey produces two. Caryophyllia Smithii, the commonest species 

 in the West of England, where it is found close to low-tide mark, 

 ranges along the eastern and northern coasts of Ireland and the 

 West of Scotland as far as Shetland, gradually increasing its depth 

 of water as it proceeds north. It has also been met with on the 

 western coast of Ireland ; but very little has been done as yet in 

 exploring the Atlantic sea-board of that island. Among the Hebrides 

 and Orkneys, the fine branching coral Oculina prolifera has on rare 

 occasions been met with, but only in deep water. Two species of Ca- 

 ryophyllia and the large scarlet Ulocyathus arcticus have been ob- 

 tained in 80 or 90 fathoms near Shetland ; the last-mentioned coral 

 has also been taken by Sars at a depth of nearly 200 fathoms near the 

 North Cape. Three other little corals have been dredged in the 

 Moray Frith, and placed by Mr. Gosse in the genus Paracyathus of 



