OCR Text |
Show 1895.] MB. F. E. BEDDABD ON NEW EABTHWOEMS. 225 The alimentary canal has, as in Kerria halophila, a gizzard, but it is rather more slightly developed. The muscular walls are only about twice the thickness of the epithelial lining; the chitinous cuticle secreted by the latter is not at all thick. As in all the other species of Kerria, there are a pair of calciferous glands in the ninth segment. The structure of these is, however, a little more complicated thau in Kerria zonalis or Kerria macdonaldi, in which species it has been figured by Eisen. The walls of the pouch are of considerable thickness and project here and there as folds into its lumen. In the thickness of the walls run numerous blood-vessels; but the tissue of which it is composed is permeated by channels which are infra-cellular. The tissue in fact looks like a closely welded mass of nephridial tubules. The miuute structure recalls that of the dorsal diverticulum of the alimentary canal in Bucholtzia, and it is-so to speak-an exaggeration of the structure which I have described in the distal part of the calciferous gland of Gorduodrilus. The oesophagus is narrow and nowhere sacculated ; its ciliation commences at the orifice of the calciferous glands. The large intestine begins in segment xii. Septal glands are present as in other species. I did not find them further back than segment vii. The anterior septa are thicker than those which follow. The stoutest are those between segments vi./ix.; but the three which come next are also moderately stout. The last heart is in segment xi. The spermathecae lie in segments viii. and ix.; they are sessile upon the body-wall, with no long stalk, nor have they any trace of a diverticulum. The extreme end of each pouch is enveloped in a thick muscular layer derived from the body-wall; this is continuous over the pouch for but a short way from the pore. The muscular sheath is so perfectly continuous with the two muscular layers of the body-wall that it is really impossible to say where the body-wall ends and where the sheath of the spermatheca begins. The lining epithelium of the spermatheca is folded and forms numerous narrow ridges. The testes, sperm-sacs, ovaries, and oviducts are of the form, and occupy the positions characteristic, of the genus. The spermiducal glands are long and coiled; the muscular part of the organ is also of considerable length. Hab. St. 204, Buenos Ayres, Baraccas do Sul, " Unter Steinen, Ufer des Elusses." (2) Kerria saltensis, n. sp. The general aspect of this apparently new species recalls that of the species Kerria halophila. But it evidently differs from that species, though not in very important points; indeed, all the American species of the genus come near together. I leave out in the following description the majority of the characters which are, so far as our present knowledge goes, of generic value and PBOC. ZOOL. Soc-1895, No. XV. 15 |