488 EDWIN S. GOODRICH. 



be closely related to Dinopliilus. It possesses five pairs of 

 pronephridia (four in the female), and a distinct ccelomic or 

 genital cavity also opening by one pair only of peritoneal 

 funnels to the exterior (Foettinger, 37). Here it seems to be 

 pretty certain that there was originally a segmented coelom ; 

 there is still a ventral chain of ganglia. 



Nemertina. 



The nephridia of the Nemertines consist essentially of a 

 longitudinal canal on either side of the anterior region of the ali- 

 mentary canal, opening to the exterior by one or by several pores 

 situated laterally at more or less regular intervals (von Kennel^ 

 63; Oudemans, 86; Hubrecht^ 59; Burger, 15, 17). Internally 

 they have been stated to open into the blood-vascular system ; 

 the latest researches, however, do not support this view (15), 

 and Biirger has shown that in several species the nephridial 

 canals give off fine branches ending in bunches of flame-cells 

 (17) (figs. 2, 3, and 24; in these diagrams the nephridia are 

 represented in the same region as the gonads). 



Altliough the development of the nephridia has not been 

 followed out in detail, Hubrecht (58) and Burger (18) have 

 traced their origin from direct invaginations of the epiblast. 



In this group of elongated worms the genital follicles are 

 numerous, and generally arranged in pairs, alternating with 

 the intestinal caeca. Each follicle communicates with the ex- 

 terior by a duct or peritoneal funnel, formed as an outgrowth 

 from its wall at a comparatively late period (figs. 2, 8, and 24). 

 It is hardly necessary to emphasise the striking similarity 

 between this metameric arrangement of follicles with their cor- 

 responding ducts and the almost identical metameric ccelomic 

 follicles and genital ducts of the Cbtetopods.^ 



Oligochteta. 



Thanks to the numerous researches of Profs. Hatschek, 



' R. S. Bergh, in 1885, in a paper wliich I have not seen, pointed out the 



reseniblauce between the genital follicles of the Nemertines and the ccelomic 



cavities of the Ciiastopods; but he considered the ducts of the follicles to be 



homologous with the nephridia of the latter group (6). 



