1903.] OLIGOCH.ETA FROM NEW ZEALAND. 225 



sometimes none. The general disposition of the perforated syn- 

 cytium 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 ai-e 

 examined under a very high magnification (such as ^2 homogeneous 

 immersion). But that this nephridium-like tube does actually serve 

 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 me one was fully mature; the segments x., xi. were 

 filled with ripe and developing sperms ; and the spermathecse wei-e 

 also filled with them ; hence copulation had recently occurred. The 

 other individual w^as 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 me that in this worm the nephridia do act as 

 sperm-ducts, as was suggested by the earlier students of Hap)lotaxis. 

 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 epi- 

 thelium, 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 ofi:' 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 Enchytrseids ; those of segment xii. open 

 laterally, near the ventral chaetse ; the other two pairs open below 



* Beddard, Trans. R. S. Edinb. xxxvi. p. 292. 



f Michaelsen, Verb, naturw. Ver. Hamburp:, 1903. 



Pnoc. ZooL. Boc— 190.3, Yol. II. No. XY. 15 



