A NEW GENUS OF OLIGOOH^TA. 479 



Sperm-sacs, two pairs, in 10, 11, racemose. 



Nephridia diffuse, a mass of tubules in the neighbourhood 

 of the pharynx aggregated into a compact gland. 



Atria lobate, each with a sac of penial setae opening on 

 to Segment 18. 



Species — D. Jacksoni.^ 



Large worm, measuring 13 inches. 



Copulatory papillae forming a dumb-bell shaped area between 

 Segments 11 and 12. 



Penial setae of two kinds, one ornamented by minute pro- 

 tuberances, the other transversely striate. 



Two pairs of spermathecae, without diverticula, in Segments 

 8 and 9 (see fig. 19). 



II. Anal Nephridia in Acanthodrilus. 



I have already (7) described some of the anatomical and 

 histological characters of the nephridia in Acanthodrilus; 

 their organs are in some species (e. g. in A. multiporus) repre- 

 sented by irregular tufts^ which are furnished with numerous 

 funnels, and numerous external orifices in each segment. 



I have now to describe a connection of the nephridia with 

 the terminal region of the intestine, which occurs in a species 

 referable, I believe, to my Acanthodrilus multiporus. 



The material I owe to the kindness of Mr. W. W. Smith, of 

 Ashburton, New Zealand. 



In fig. 1 of PL XXXIII, is represented half of a portion of the 

 posterior end of the body of one of these worms, comprising 

 about thirty segments. The body was divided by a cut at 

 right angles to the dorso-ventral axis ; the intestinal canal is 

 laid open, and the typhlosole is seen to occupy the dorsal line 

 of the intestine. The figure is twice the size of nature. 



The typhlosole ends abruptly about an inch in front of the 

 anus ; a faint streak is, however, recognisable, extending for 

 perhaps a quarter of an inch beyond the end of the typhlosole. 



1 Named after Mr. W. Hatchett Jackson. 



