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Show 1903.] OLIGOCH.ETA FROM NEW ZEALAND. 225 sometimes none. The general disposition of the perforated syncytium is very similar to a nephridium, and the canal takes a course similar to the latter tube, but is not quite so undulating. The canal bears cilia throughout its whole extent. So similar is this sperm-duct to a nephridium in this worm, that the differences are only perceptible when the organs are examined under a very high magnification (such as j-^ homogeneous immersion). But that this nephridium-like tube does actuallyserve as a sperm-duct, is demonstrated by the presence of sperms within the canal, and the fact that in the case of one funnel I noted spermatozoa entering the mouth of the canal. Though I traced the ducts to the body-wall, I was quite unable to detect the pore in either sperm-duct; nor was Michaelsen successful in finding the actual aperture in H. gordioides. Of the two individuals obtained by m e one was fully mature; the segments x., xi. were filled with ripe and developing sperms ; and the spermathecse were also filled with them ; hence copulation had recently occurred. The other individual was quite immature, although the three pairs of gonads and the ducts, were present; in this individual, likewise, there are no nephridia (unless the sperm-ducts are nephridia) in segments xi., xii., xiii. It appears to m e that in this worm the nephridia do act as sperm-ducts, as was suggested by the earlier students of Haplotaxis. There are two median sperm-sacs, in the form of simple pouches, formed by the septa x./xi., xi./xii., which are pushed backwards above the gut so as to reach into segments xii., xiii. respectively. Each of the sperm - sacs is filled with developing and ripe spermatozoa. There is but a single pair of ovaries and oviducts : the former in segment xii. ; the latter opens in about the middle of segment xiii. The oviduct is a wide tube surrounded by a ciliated epithelium, and opens by a wide funnel into segment xii. This duct is present in the immature specimen, and can be seen traversing the anterior half of segment xiii. The presence of a single pair of female organs marks off this species from the two other known representatives of the genus ; and in this respect our species resembles Pelodrilus, an allied genus, originally founded by Beddard * for a New-Zealand worm, P. violaceus ; but the discovery by Michaelsen f of P. ignatovi from Central Asia, in which the two pairs of sperm-ducts open on independent segments, forms a passage to Haplotaxis. But in all other characters this new species agrees with the diagnosis of Haplotaxis and differs from that of Pelodrilus. A single median ovisac, filled with eggs, passes backwards through segment xiii. In segments xi., xii., xiii. are paired copulatory glands, similar to those present in some Enchytraeids ; those of segment xii. open laterally, near the ventral chaetae ; the other two pairs open below * Beddard, Trans. R. S. Edinb. xxxvi. p. 292. f Michaelsen, Verh. naturw. Ver. Hamburg, 1903. PROC ZOOL. Soc-1903, VOL. II. No. XV. 15 |