| OCR Text |
Show 40 DR. W. UAIRD ON A NEW EARTH-WORM. [Jail. U, doubled upon itself so as to make a perfect square, and sewn up so that two contiguous sides are closed, and two open, the closed sides being behind and below, and the open sides above and in front. The two upper free borders are connected with strong rods, moving upon one another at the angle when the net is opened or closed. At the lower and anterior angle a weight, generally consisting of a perforated stone, is appended, and the apparatus is complete. With this net one or two men dive into a deep part of the river, near a bold shore ; immediately also some others disappear, and, having remained a considerable time under water, pop their heads up one by one, after which the net is drawn up on a shingly bank with the Ika loa floundering within it. DESCRIPTION OF PLATE I. Fig. 1. Lateral view of Gonostomyxus loa loa (the type specimen is contained in the Haslar Museum). About one-third of the natural size. 2. Inferior aspect of the head, with the mouth open to show the cresentic palatal membrane and the sucker-like plicated band within the border of the lower lip. 3. A scale from the shoulder, magnified about 8 diameters to show its ctenoid character and the mucus-groove on its deep surface. 3. Description of a new Species of Earth-worm (Meyascolex diffringens) found in North Wales. By W . B A I R D , M.D., F.R.S., Sec. The genus Perichata was formed by Schmarda to include a number of species of earth-worms differing from the more common genera in having each segment of the body marked in the centre by a narrow, raised rim, which is beset, for the whole circumference of the body, by a row of spines or setae. He describes, in his ' Neue wirbellose Thiere,' four species, all natives of Ceylon. In 1845 Dr. Templeton characterized a new genus of earth-worms, natives also of Ceylon, which he called Meyascolex. This genus consisted at that time of only one species, a native of the alpine regions of that island, aud is distinguished, like Pericheeta, by a row of small spines or setse surrounding each segment. This row, however, according to Dr. Templeton's description (see Ann. & Mag. of Nat. Hist. vol. xv. p. 60) is not completely circular, the setae being deficient in the mesial line of the back for about the tenth of an inch. Schmarda, who considers the two genera distinct, does not quote Templeton's description accurately ; for he seems to think that that naturalist describes the ridges on each ring as occurring only on the back-whereas he distinctly says they surround the body, only that the rows of bristles are not continued round the whole circumference but are deficient for a short space on the back. In describing the genus Pericheeta, Schmarda says that the species he describes possess no cincture or girdle, whereas in P. cingulata |
