170 MR. F. E. BEDDARD ON A LARGE KARTHWORM. [Mar. 16, 



area are bounded by the ventral pair of setae ; this area, which is 

 distinguished by its very pale colour, surrounds the male genital 

 apertures, which are upon the 17th and 19th segments respectively 

 (see fig. 2). In A. ungulatus the clitellum extends from 14-17 

 inclusive and the male genital apertures are upon the 18lh and 

 20th segments ; in A. ohlusus the clitellum is unknown, the male 

 genital pores are upon the 1 9th and 21st segments. 



Dorsal pores are stated by Perrier to be present in his two species ; 

 in my species they are present and commence apparently at the 13th 

 or 14th segment ; in one specimen the first dorsal pore was visible 

 between the 12th and 13th segments, in a second specimen this pore 

 was a segment further back. I have figured these apertures as 

 extending over the cUtellum, since they were visible on these 

 segments in immature examples without a clitellum ; when the 

 clitellum was present they were apparently absent or, rather, perhaps 

 rendered invisible by the swollen glandular integument. 



In Acanthodrilus multiporus (see P. Z. S. 1885, pt. iv. p. 810) I 

 observed dorsal pores commencing after the clitellum, the first pore 

 marking the posterior boundary of that region of the integument. 

 In Acanthodrilus dissimilis and A, novtezelandire tbey appear to be 

 present though very inconspicuous ; I only noted them after the 

 clitellum. 



In the furrows separating segments 7-8 and 8-9 were a pair of 

 distinct rounded apertures corresponding to tl>e inferior pairs of 

 setae ; these are the apertures of the copulatory pouches. The pair 

 of setse on segment 8 were in most instances greatly modified, 

 being much larger and more conspicuous than the other setae of the 

 body ; their appearance is very like that of the genital setae on 

 segments 17 and 19. 



In describing the structure of the genital organs I shall call 

 attention to those setae which correspond to internal structures entirely 

 novel in this genus. 



The ordinary setae of the body are distributed in pairs as iu other 

 species of the genus. 



Tlie apertures of the nephridia are very conspicuous and correspond 

 in every case to the more dorsal pair of setae. 



The female generative pores are displayed in fig. 2 ; they are a 

 pair of very minute pores situated on the 14th segment in front 

 of and to the inside of the ventral pair of setae ; their position is 

 nearly similar to the corresponding pores of A. novee zelandics ; they 

 are on the same segment as in that species, where, however, the pores 

 are placed in front of the outermost of the two ventral setae. In 

 Acanthodrilus capensis I find the female generative pores are upon 

 the 14th segment and the ovaries in the 13th segment, and not, 

 as erroneously stated in my paper on that species ', in the segment 

 anterior to these ; in the present species, however, the pores are 

 placed in front of the innermost of the two ventral setae. 



Vascular System. — In fig. 7 ot Plate XIX. is illustrated the main 

 vascular trunks of the anterior region of the body. The dorsal vessel 

 1 Proc. Roy. Phys. Soc. 1885-6, p. 369. 



