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Show 1892.] SPECIES OF EARTHWORMS. 677 but in segments xiv. and xv. the oesophagus becomes wider, and its lining membrane much folded and very vascular. This region evidently corresponds to the calciferous glands of other Earthworms : all doubt upon the matter appears to be removed by the discovery of crystals exactly similar to those which occur in the calciferous glands of other Oligochaeta. The vascularity of the oesophagus is not limited to these two segments; from the tenth segment onwards its walls are vascular, though not so folded as in the two segments xiv. and xv. The intestine commences in the xviiith segment. The gonads occupy the usual position; the sperm-sacs are in segments ix., x., xi., xii. The atria are like those of other Acantho-drilidae, and each is provided with a bundle of penial setae. These setae (Plate X L V I . figs. 9 and 10) are recurved at the extreme end; the extremity has two delicate wing-like processes which, when the seta is viewed from above, give to the end an oval contour ; the tip of the seta in this aspect is seen to be bifid. The absence of any ornamentation upon the setae appears to distinguish the N e w Zealand Acanthodrilidae with the exception of Octochcetus antarcticus, where it is only very slight. The spermatothecae are, as is nearly universally the case with the Acanthodrilidae (Acanthodrilus [Diplocardid] communis is, so far as I a m aware, the only exception), two pairs situated in segments viii. and ix. Each pouch has three small diverticula, one of which is constantly in front of the septum. 4. Acanthodrilus paludosus, n. sp. This is a small and slender worm, but I have not preserved any accurate notes of its dimensions ; it was about an inch in length and something like 1 m m . in diameter. It was found in a marsh in N e w Zealand by M r . W . W . Smith, to w h o m I a m indebted for the specimen. This species is a near ally of Acanthodrilus annectens, which I have already referred to as possibly worthy of generic separation from the Acanthodrilidae with paired nephridia. The present species has the same arrangement of the setae, which are not modified upon any of the segments of the body. I did not describe, in m y account of Acanthodrilus annectens1, the fact that only one of the two ventral setae is missing on the segments which bear the atrial pores, i. e. xvii. and xix. ; the apertures take the place of the missing outer seta of the ventral couple ; on the xviiith segment both setae of the ventral pair are present; the pore itself lies to the outside of the pair. Acanthodrilus paludosus shows exactly the same arrangement, and both species therefore differ from Acanthodrilus smithi and from the other N e w Zealand species of Acanthodrilus in this matter: in them the ventral setae are entirely absent from the xviith and xixth segments. The clitellum was not developed, though in other respects the . worm appeared to be fully mature. 1 " O n the Structure of three new Species of Earthworms &c," Q. J. M. S. vol. xxix. p. 102. |