Page:The Zoologist, 1st series, vol 1 (1843).djvu/281

Rh Having thus glanced at some of the reptiles of foreign countries, we may proceed to such as are indigenous in these islands, and to which, more properly, Mr. Bell's volume is appropriated.

may not, perhaps, be altogether uninteresting to some of your readers, to have pointed out to them a few fresh localities for this beautiful mollusc, which is now becoming generally diffused over the rivers and canals of England. The precise time of its introduction will probably never be correctly ascertained, although its appearance in one place, as a centre from which radii diverge in different directions, may in some degree tend to elucidate its history. Many habitats for this species are mentioned by H.E. Strickland, Esq., in a paper published in the second volume of Charles worth's continuation of Loudon's 'Magazine of Natural History.' The place to which I would particularly direct your attention, is the Port of Goole, in Yorkshire, belonging to the Aire and Calder Company, where are several large docks for the reception of shipping, and which, I believe, were opened either in 1828 or 1829. In three or four years after this, I was greatly surprised, on seeing the water drawn off a few feet lower than usual, to find the walls of the docks completely covered with this shell; and 1 do not at all exaggerate when I say, that without much difficulty, pecks might readily have been procured. Here they are to be seen attached by their byssus, not only to the walls, but to stones, fragments of wood, the live shells of Anodon Cygneus, and the dead ones of their own species; and from the numbers of the latter now to be found, it is quite evident that many generations have passed away. One dock is entirely appropriated to the bonding of foreign timber, which frequently remains some months prior to its being reshipped, or floated on rafts down the rivers or canals to the various inland towns; during which time, those pieces which adjoin the sides or touch the bottom are sure to be covered over by this shell. Hence it naturally follows that its distribution over the West Riding of Yorkshire, and the adjacent counties which have any communication with the canals of the Aire and Calder Company, will fail to excite sur-