. A catalogue of the British non-parasitical worms in the collection of the British Museum. Worms. APPENDIX. 297 rounded at the tip, where a small slit marks the situation of its toothless mouth. There are no eyes. The third and fourth seg- ments are elongated, but the others are nearly equal, being, when at rest, about one-eighth of an inch in length and in breadth ; the pro- No. XLVIII.—Meckelia a. Natural size, and in a state of quiescence, shaded, to show the lateral pale lines. b. The head slightly magnified and c. A small portion of the tube. portions, however, varying much ac
. A catalogue of the British non-parasitical worms in the collection of the British Museum. Worms. APPENDIX. 297 rounded at the tip, where a small slit marks the situation of its toothless mouth. There are no eyes. The third and fourth seg- ments are elongated, but the others are nearly equal, being, when at rest, about one-eighth of an inch in length and in breadth ; the pro- No. XLVIII.—Meckelia a. Natural size, and in a state of quiescence, shaded, to show the lateral pale lines. b. The head slightly magnified and c. A small portion of the tube. portions, however, varying much according to the degree in which the body, or particular portions of it, are extended. When mag- nified, the margins appear finely crenulate. The anus is simple and terminal. Meckelia annulata was found within a coarse tube attached to an old'valve of the Venus islandica of British authors. The tube was about 4 inches long, formed of a membrane, smooth, and iridescent internally, but coated on the outside with gravel and pieces of broken shells, and open at both ends. 1 have found a very different worm in a similar tube; so that a doubt may, perhaj)s, be entertained, whether the Meckelia fabricates it of itself, or is merely a tenant at will. From the body being distinctly annular, the worm is brought in contact with the Annelides; but its softness, the want of feet or bristles, the apparent simplicity of its structure, and its resemblance to the tapeworms, and more especially to the Linens longisshnus of Sowerby, favour its claim to be placed among the Vermes. Another, and a very fine specimen, was of a chocolate-red colour, tinted purplish-red on the sides, and the ventral surface was of the latter colour throughout; but the most remarkable difference was that there was a white line down the middle of the belly as distinct as that down the back. All the specimens seen by Sir J. G. Dalyell had the abdominal white line. This is exactly opposite the dorsal line, so that the line
Size: 1746px × 1430px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, booksubjectworms, bookyear1865
