57 



ducts are at least eight times as long as the funnels. The duct runs at 

 first back for three somites, turning in XV and then paralleling itself. 

 In XII it is coiled several times, and then, entering in XI, joins the fun- 

 nel. It is, however, quite narrow, about one-sixth the width of the 

 funnel. In longitudinal section of the body the funnel is seen to be in 

 length two-thirds the transverse diameter of the body and about two- 

 thirds as wide. The sperm -duct possesses an atrial chamber some 

 little distance from the male-pore (pi. ix, fig. 5). 



Dorsal vessel rises from the intestine in somite XIV, but does not 

 always separate itself at once. Thus, in one specimen it was fully 

 separated in XIV, in another in XV. 



Testes small, solid, in XI ; ovaries long, in XII. Two sperm -sacs, 

 tubular in form, extending from XII to XV. Ovisac extends as far 

 back as XVII. 



Spermathecce large, each with two large club-shaped diverticles 

 projecting from the center (fig. 29, e). Ampulla of the spermatheca 

 twisted, and sigmoid where it connects with the intestine from the 

 ventral side. 



Nephridia (fig. 30, a and b) consist each of three more or less 

 indistinct lobes. To these must be added a posterior helix-like spur, 

 probably analogous with the spur in the Megadrilid genera (Eisen 16). 



The tubules wide and closely wound, as in other species of Mesen- 

 chytrtzus. It is apparent that the nephridium is built somewhat as in 

 the higher Oligochaeta, and there is possibly a * bridge ' starting out 

 from the helix-like spur. The ducts of the spur are much thicker 

 than those in other parts of the nephridium. 



Lymphocytes (pi. ix, fig. 3). Of at least three different shapes 

 and of various sizes round, oval, or crescent-shaped. The structure 

 appears to be the same in all and I am unable to say whether we have 

 three distinct forms or only variations of one and the same variety. 



MESENCHYTRyEUS BERINGENSIS sp. nov. 

 pi. x, figs. 1-3; text-fig. 31. 



Definition. Length 15 mm., width .75 mm. Somites about 70. 

 Seta sigmoid : laterals, 2, 2, 3, 4, 2, 3, 2, 3, 3, o, o, 4, 3, 3, 3, 3, 3, 

 3, etc., 4, 4, 4, 5, 4, 5, 5, 4, etc. ; ventrals, 5, 5, 6, 7, 6, 5, 6, 7, 6, 

 o, o, 4, 5, 5, etc., 5, 6, 7, 6, 5, etc. Prostomium pointed. Head- 

 pore near apex. Clitellum, XI, XII and XIII. Sexual papillae large. 

 Scptal glands in IV to VI. Brain tapering posteriorly ; posterior 

 margin almost straight. Dorsal vessel rises posterior to clitcllum. 



