1894.] NEW GENERA OF BAETHWOBMS. 385 



rather thin-walled, hut have a stout duct leading to the exterior. 

 I could not see the least trace of a diverticulum. It is rare for 

 the members of the family Cryptodrilidse, indeed for any worm 

 belonging to the Megascolicidae, to be without diverticula to the 

 spermatheca. There are here and there a few cases, but these are 

 mostly of worms which have a simple structure and are perhaps 

 rather degenerate in their organization. Examples are furnished 

 by the genera Gordiodrilus and Ocnerodrilus. I know of no large 

 and well-developed genus like Millsonia in which the spermathecaB 

 are devoid of diverticula. It may of course be that there are 

 really diverticula, but that they are concealed in the thickness of 

 the muscular walls of the duct of the spermatheca. 



Millsonia nigra, n. sp. (Fig. 1, p. 381.) 



Def. Length 230 mm. ; diameter 7 mm. Male pore single. 

 Spermiducal glands open each into a bursa copulatrix. 



External characters. — This species, judging from the single 

 specimen at my disposal, is rather smaller than the last. It is 

 also rather different in colour, being of a dark brown thoughout, 

 almost black in parts. The setse, dorsal pores, and prostomium 

 are as in the last species ; the chteUum was undeveloped. The 

 most salient external difference, apart from colour, that distinguishes 

 this species from the last is in the orifices of the male organs. 

 The male pore, as stated in the definition of the species, is single 

 and median. It is of some size and occupies an area equal to that 

 which would be occupied by the missing ventral setae of its 

 segment. It is surrounded by a smooth area of skin, doubtless 

 the commencement of the otherwise wanting clitellum. The 

 spermathecal pores are also fairly conspicuous, but they are paired, 

 though the orifices are very close together. These orifices 

 correspond in position to the ventral setse. They are on the 

 boundary line of segments viii./ix., though, as will be pointed out 

 later, the pouches themselves lie principally in the viith segment. 



Intersegmental Septa. — The character of the septa plainly 

 distinguishes this species from the last. They commence at the 

 same segment, i. e., between segments iv./v., but they are from the 

 first thickened ; the last of the series of thickened septa separates 

 segments xiii./xiv. Numerous stout muscular strands tie them 

 together and to the parietes. These bands are found also attached 

 to the septa separating segments xiv./xvi. 



JS'ephridia. — This species shows the peculiar character of the 

 nephridia better than does the last. On opening the body the 

 nephridia of the anterior segments were seen to present the usual 

 characters of the diffuse nephridia ; those of the fourth and fifth 

 segments seemed to be a little thicker than the others, but whether 

 these formed a compact " peptonephridium " I am unable to say. 

 Elsewhere (in the anterior segments) the nephridia were scattered 

 tubules not quite so densely packed as in Millsonia rubens. Further 

 back the coiled masses of tubes seem to disappear and to be 



