264 BALANID.E. 



Range, habits, fyc. — I have received specimens from all parts of the 

 coast of Great Britain and Ireland, generally attached to Crustacea and 

 mollusca, and never hitherto from rocks uncovered by the tide. This 

 species is also attached to floating timber, sticks, fuci, and occasionally 

 to pebbles at the bottom of the sea. Mr. Thompson has sent me spe- 

 cimens from twenty-five fathoms depth in Belfast Bay : others on a 

 Pinna from about fifty fathoms on the coast of Antrim ; others from 

 between three and six fathoms attached to Laminaria digitata: there 

 is a specimen in Mr. Jeffreys' collection marked forty-five fathoms. It 

 is often associated, both on the coasts of America and Britain, with B. 

 porcatus, and though these species are so distinct, yet when both have 

 their surfaces similarly affected by being attached, as is often the case, 

 to large Pectens, it is not at first easy, by external characters, to dis- 

 tinguish them, except by close inspection of the terga, which in B. 

 porcatus are beaked and purple. The B. crenatus is sometimes 

 associated in deep water with B. Humeri. At Ramsgate, in Kent, I 

 saw a rudder of a ship, in which the two or three upper feet were 

 thickly coated with B. balanoides, and the two or three lower feet 

 with B. crenatus and improvisus mingled, together with a few of B. ba- 

 lanoides : occasionally vessels are thickly incrusted with this species, 

 but I have never seen an instance of its concurrence with B. tintinnabu- 

 Ivm and amphitrite — the commonest species on ships coming from the 

 south. I have seen specimens from Greenland, Baffin's Bay, the coast 

 of Labrador, and other specimens marked simply, "Arctic regions," 

 and, again, others from the shores of Maine and Massachusetts. 

 The arctic specimens, and those from the northern United States, are 

 larger than the British. I have seen one single minute specimen on a 

 crab, marked as having come from the Mediterranean. In the British 

 Museum^ amongst some specimens of B. eburneus, ticketed as having 

 been sent from Jamaica, there was a small group of specimens, differing 

 in no one essential respect from the common varieties of B. crenatus : 

 at iirst I concluded that this was an erroneous habitat, and that the 

 specimens had really come from the United States, where B. ebiu-neus, 

 is found as well as in the West Indies : for it appeared to me 

 exceedingly improbable that an animal which can exist in lat. 7o° N. 

 should inhabit the hot shores of Jamaica : but subsequently I have re- 

 ceived a specimen from Prof. Krauss, collected by himself in Algoa 

 Bay, which is perfectly characterised, and even has the little cells in 

 the furrow T under the sheath : so that [ am compelled to admit this 

 enormous range and cabability of resisting the most extreme climates. 

 That this species should live in the tropical seas is the more surprising, 

 as the large size of the specimens in the northern seas and in the glacial 

 deposits, might fairly have been supposed to have indicated special 

 adaptation for a cold climate. The great geographical range of this 

 species accords with its range in time from the present day to the Co- 

 ralline Crag period. 



The specimens from the glacial deposits which I have examined, 

 chiefly in Sir C. Lyell's collection, are very fine and large ; they are 

 often associated, like the now living individuals, with B. porcatus and 

 Humeri: they come from the well-known formation of Uddevalla and 



