286 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Olignchaeta. 



Testes and ovaries are normal. There are two sperm-sacs, in 9 and 12, small 

 and much lobulatcd. In the series of longitudinal sections I see a third pair in the 

 13th. of small size, but whether this is normal I cannot say. 



The prostate is a curved, subcylindrical gland, confined to its segment, rising 

 up so as to overarch the intestine (Plate XI, fig. 34). Its surface is rough, and the 

 lumen is simple — i.e., does not branch — ^though at intervals it receives the necks of 

 groups of gland-cells, which open into slight diverticula, which, however, cannot 

 be traced as definite luraina. 



The epithelium lining the very narrow lumen of the prostate consists of tall, 

 narrow columnar cells, beyond which is a layer of fibres of extreme fineness, due 

 either to a connective tissue or, more probably, to the necks of the gland-cells being 

 cut across at various planes as they curve towards the canal. 



In the neighbouring segments there are well-developed dorso-ventral muscles 

 (" arcuate muscles "), but there are no penial chaetae. 



Two pairs of spermathecae lie in segments 8 and 9, opening at the level of chaeta e. 

 The ampulla is large ; the diverticulum single and small, on the anterior median 

 side of the duct (Plate XI, fig. 35). 



Locality. — Adams Island ; 2,000 ft. ; under stones ; (Speight). 



Diporochaeta perionychopsis, sp. nov. (Plate XI, figs. 36-39.) 



About eighteen specimens were collected from various parts of the Auckland 

 Islands. The greater number are immature. 



Colour. — In life the worm is " deep crimson-red," but in formol the colour has 

 changed to a reddish-purple, and even brown later, with paler clitellum. 



The dimensions of mature individuals reach a maximum of 225 mm. in length, 

 with a diameter of 6 mm., and contains 200 segments. Others are slightly smaller. 



Prostomium half epUobic, without a transverse groove. The preclitellar seg- 

 ments are not annulated ; the posterior ones are triannulate. 



The chaetae are about 50 to 60 per segment, with a small ventral and smaller 

 dorsal gap. They are similar in size all round the body. The chaetae are more 

 numerous in the preclitellar than in the postclitellar segments, thus: — 



NuMBBB OF Chaetae in corkesponding Segments in Three IndividuaiiS. 



The diteUum is saddle-shaped, and covers segr^ents (13), 14-18, but it is not 

 developed in the majority. 



Genital Pores, &c. — In the most fully developed specimen I see no papilla on the 

 18th. This segment is grooved transversely in its middle, and I believe I can detect 

 a minute pore at the lateral margin of the groove on each side, in line with the chaetal 

 row, just mediad of chaeta a. 



