1885.] NEW-ZEALANU KARTHWORMS. 829 



vasa defereutia, and are consequently not obvious on a dissection of 

 the wornn, since they are largely concealed by the funnels and are 

 only evident on raising the latter. In transverse sections (Plate LI I. 

 fig. 9) they are very conspicuous, and although attached by a pedicle 

 to the sides of the funnel, their tissue is unmistakably different from 

 the elongated cihated cells which compose the latter, and is absolutely 

 similar to that of the homologous glands in the other species ; the 

 change in the position of the glands naturally moves them a segment 

 further forward than in A. dissimilis, and there is consequently a 

 segment lying between the ovaries and the posterior pair of glands. 



Copulafory Pouches. — Copulatory pouches (spermathecae) are 

 present in all three species, and have a characteristic form which 

 serves to discriminate the species. In all there are two pairs which 

 are situated in the 7th and 8th segments, and open on to the 

 exterior in the furrow which separates each of the segments from 

 the preceding one, in front of the ventral pair of setae; in A. tnulti- 

 porus the apertures of the copulatory pouches are related to the 

 outermost of the two ventral setse. The copulatory pouches are 

 large oval sacs, communicating with the exterior by a short, thick- 

 walled duct. In A. multiporus the pouches appeared to be without 

 diverticula ; in A. dissimilis each of tlie copulatory pouches (Plate 

 LIII. fig. 9) is furnished with a pair of long diverticula opening into 

 the duct of the pouch, one on either side. The disposition of the 

 diverticula varied in different specimens : in one specimen the diver- 

 ticula were contained in the same segment as the pouch, with the 

 exception of one of the two diverticula of the posterior left-hand 

 pouch, which passed through the mesentery and projected into the 

 8th segment; in another example both diverticula of the two anterior 

 and one of the posterior pouches, in the segments anterior to those 

 in which the pouches themselves were situated. In A. novce 

 zelandiee the terminal portion of the duct of tlie copulatory pouch 

 is beset with a great number of small diverticula arranged in the 

 form of a rosette (Plate LIII. figs. 3 and 8) ; as in^. dissimilis, the 

 diverticula sometimes seem to lie in the same segment as the copu- 

 latory pouch itself, sometimes in the segment in front. 



In Acanthodrilus dissimilis the structure of the copulatory pouches 

 and of their diverticula undergo certain changes during the life of 

 the animal, which are evidently connected with the process of 

 fecundation. 



In individuals, which I take to be not completely mature, the 

 copulatory pouch has the structure illustrated in Plate LII. fig. 8 ; 

 within the muscular layers, which are thin and abundantly vascular, 

 is a layer of tail, columnar, nucleated cells ; on a superficial view 

 these cells present the appearance indicated in fig. 7 of the same 

 Plate ; they are extremely narrow and somewhat hexagonal in 

 contour ; the epithelial lining of the copulatory pouch is thrown 

 into folds which are often very regular in their arrangement 

 (Plate LIII. fig. 7), but only consist of a single layer of cells. 



In another individual the structure of the epithelium of the 

 copulatory pouch is somewhat more complicated : a small portion 



Proc. Zool. Soc— 1885, No. LIV. 54 



