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Show 386 MR. F. E. BEDDARD ON THE [Apr. 19, Lumbricidae; the testes and vesiculae seminales conform in every respect to Lumbricus or Perichata ; the position of the gizzard, the presence of calciferous glands on the posterior region of the oesophagus, the extent of the clitellum and the relations to it of the male generative apertures, all point to the resemblance of this genus to many Intraclitellian forms. The presence of the peculiar epidermic structures believed by Vejdovsky to represent abortive setae, ally Eudrilus to Urochata in particular among the Intraclitellians. The origin of the lateral " hearts " from the dorsal vessel, and not from a supra-intestinal trunk, is a point iu which Eudrilus as distinctly assimilates to many Postclitellians and Intraclitellian worms. The muscular penis of Eudrilus is, however, in m y opinion, not to be regarded as a new structure; in many species of Perichata the terminal portion of the vas deferens is a thick-walled muscular tube which can be everted, and which doubtless serves as a copula-tory organ ; from this condition to that which is characteristic of Eudrilus is not a wide step, the everted condition of the terminal section of the vas deferens being permanent in the latter genus. Another point of difference from the remaining Lumbricidae is in the number of accessory organs which open iu common with the vasa deferentia ; it must be remembered, however, that the vasa deferentia retain their distinctness up to their point of opening on to the exterior, and the presence of two prostate glands is therefore not surprising. It is also possible that there is a similarity in this respect between Eudrilus and Perichata ceylonica \ only that in Eudrilus all the accessory male glands are concentrated, and come to open on one segment in common with the sperm-ducts. The female generative apparatus, however, appears to be absolutely unique ; there has been nothing like it described in any other Earthworm. So far as our present knowledge goes, it seems necessary to separate Eudrilus into a distinct family. Perrier himself has shown reasons for believing that different species of the genus may have the male generative openings either within or behind the clitellum, and in any case Eudrilus shows no marked affinities to any Postclitellian or Intraclitellian genera. I am unwilling, however, at present to regard Eudrilus as the type of a new family equivalent to either Postclitellians or Intraclitellians, and I think that Vejdovsky's plan of dividing the Oligochaeta terricola into several families (Perichaetidae, Urochsetido., &c.) is most in harmony with our present knowledge of the structure of the group. The present species cannot be identical either with any of those described by M . Perrier, or with a fourth species recently described by myself, from New Caledonia. It differs iu the position of the nephridiopores, which open in front of the ventral pair of setae, and not by the dorsal pair as in all the other species of the genus at present known. If M . Perrier had not, in his description of the genus, particularly stated that the nephridiopores are developed in relation to the dorsal setae, I should have referred this species to E. peregrinus. ] Ann. & Mag. Nat. Hist. 1886, xvii, p. 89. |