Oligochaeta.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 259 



marked off fi'Diii tlie cuticulated and much lower cells of the buccal region. I do not 

 recall any pharynx having this simple structure. 



The narrow oesophagus passes gradually into the intestine, whicli is only dilated 

 behind the ovisac in the 24th segment. 



The nephridia are small, and recall those of Enchytraeids in structure. A 

 small preseptal region ; a more or less triangular post-septal region, as seen in longi- 

 tudinal sections, with a wide but short duct leading from the posterior end. The 

 lumen passes in an undulating course through a mass of cells, few in number. The 

 hrst pair lies in segment 7, tlie next in 9, the third in 13, and then they occur in each 

 of the following segments. 



Testes. — One pair in 10. Large \\ide funnels lie on tlie hinder septum ; each 

 leads into a short straight sperm-duct, which passes directly backwards along the 

 ventral body-wall, below the ovary, to enter the apex of a penial apparatus 

 (Plate X, fig. 7). The wall of the duct is covered with groups of gland-cells, as 

 described and figured by Goodrich for B. pilosus, and such as are familiar in prostates. 

 This covering commences immediately behind the septum 10/ 1 1, and ceases as the duct 

 curves upwards at the hinder end of the segment to enter the penial sac. The thin 

 muscular wall of this sac is attached to the dorsal body-wall of segment 12 by a 

 group of retractor muscles arising from its apex, which pushes the posterior septum 

 (jf segment 13 backwards ; the cavity of the sac. close to its proximal extremity, is 

 traversed by a few bimdles of fibres of, apparently, connective tissue. The sperm- 

 duct passes through the sac, and is divisible into two regions which differ structurally 

 from each other : first it dilates into an ovoid glandular bulb ; then the wall becomes 

 thin and folded to form the penis, which opens into a small penial chamber unpro- 

 vided with any chitinous lining ; this in its turn commimicates witli the exterior by 

 a comparatively small pore in segment 11. It is to the wall of this chamber that the 

 fibres above mentioned are attached. The structure of the duct alters as it traverses 

 this sac. At first, just after entering the sac, the wall is formed of small ciliated 

 cells of the usual type ; after reaching the interior of the sac the cells elongate con- 

 siderably, so that the diameter is now more than twice what it is outside the sac, 

 but the lumen remains small : the cells are still ciliated (Plate X, fig. 4). This 

 region forms a large bulb or swelling in the course of the duet. Further down, the 

 cells decrease in height, and lose their cilia and granulation, so that at the lower 

 end they are quite low, and the lumen becomes much wider (Plate X, fig. 6). 

 This region is somewhat folded, indicating its protrusibility. The duct opens on a 

 slight papilla into a small penial chamber, an invagination of the epidermis. 



Tli(>re are sperm-sacs in 9, and an unpaired one passing through segments 11 

 to 19. 



The ovaries and oviduct lie in the normal positions. An unjiaired ovisac extends 

 through segments 19 to 23. 



Spermathecae. — A pair in segment 10, with widely separated pores. Each 

 spermatheca (Plate X, fig. 3) is distinctly divided into two parts, a smaller and a 

 larger ; the larger is posteriorly directed, somewhat ovoid in shape, with a jjointed 

 end and wide base, which is deeply constricted from the smaller globular anteriorly 

 situated portion ; the latter communicates by a very small aperture with an invagi- 

 nation of the epidermis, winch has the form of a short tube, into which the pore of the 

 globular sac projects slightly. The ovoid ampulla is lined by low cells, except at its 



