1885.] NEW-ZEALAND EARTHWORMS. 813 



in which there are four male generative apertures is MoniUgaster, 

 but in this genus the position of the orifices is different, and the 

 anatomy of the worm is in other respects quite different from that 

 of Acanthodrilus. 



ACANTHODRILUS NOV^E ZELANDI^, n. sp. 



Setae disposed as in Lumhricus in four series of pairs. Clitellum 

 occupies 8 segments (12-19 inclusive) ; it is saddle-shaped, having a 

 ventral area upon which there is no glandular development ; on 

 segments 16 and 18, corresponding to ventral row of setae, are male 

 genital apertures through which penial sette protrude. The apertures 

 of the copulatory pouches are between the Gth and 7th and between 

 the 7th and 8th segments. The apertures of the oviducts are 

 paired, and upon the 14 th segment. 



The apertures of the nephridia alternate in position from segment 

 to segment, sometimes they are in front of the dorsal, sometimes of 

 the ventral pair of setae. The nephridia are furnished with a long 

 muscular duct and a minute diverticulum, or have a large diverti- 

 culum and no muscular duct ; the former are the dorsal series, the 

 latter the ventral. The dorsal vessel is formed of two trunks 

 anteriorly, which unite where they perforate the intersegmental 

 septa. The intestine is uuproviJed with caeca or glands of any 

 description. The testes are two pairs of racemose glands in seg- 

 ments 11 and 12 ; the vasa-deferentia funnels open in segments 10 

 and 1 1 ; the external apertures of the vasa deferentia are accompanied 

 by a bundle of penial setse and long coiled tubular prostatic gland ; 

 the ovaries are in segment 13 ; the oviducts perforate the mesentery, 

 dividing this from segment 14. There are two pairs of sperma- 

 thecae in segments 7 and 8 ; each is a round sac with a short duct, 

 round which are clustered a group of accessory diverticula. 



Acanthodrilus dissimilis, n. sp. 



This species is very closely allied to the last, and only differs, so 

 far as I have been able to make out, in tw o points. The dorsal vessel is 

 a single tube, and the copulatory pouches are furnished with only a 

 single pair of large diverticula, one on either side. 



Acanthodrilus multiporus, n. sp. 



This species differs considerably from the two last. Like A. 

 novcB zelundice, it attains to a length of from 10 to 12 inches and \ an 

 inch in diameter. The setas are disposed in eight equidistant rows 

 of a single seta each. The clitellum occupies the same segments as 

 in the last species, and the male genital apertures have the same 

 position and correspond to the outermost of the two ventral setae ; 

 there are no special penial sette. The apertures of the spermathecae 

 are between 7 and 8 and between 8 and 9 ; they correspond in 

 position to the outermost of the tvro ventral setae. 



The sperniathecte appear to be simple spherical pouches without 

 any diverticula. The nephridia are small and delicate ; each segment 

 is furnished with 8 nephridial pores corresponding to the 8 setse ; 



Proc. Zool. Soc— 1885, No. LIII. 53 



