Camekon. — ycpltridiiiin of Maoridrihis i-osac liiihUird. 



179 



irregular. The examiuation of .Sections, however, enal)le.s one to rectify 

 one's ideas on this matter. 



The marginal cells are much shorter and less specially arranged than 

 in other genera, but are, as usual, provided with cilia which project into the 

 coelom and are shorter than those borne by the central cell. The marginals 

 pass round the sides to the front of the funnel, decreasing only very slowly 

 and very slightly in height, and here join the cells of the canal-wall. 



The dorsal lip is formed by the central cell (figs. 4, 5, o .cc), capped by the 

 short marguials ; the ventral lip merely by the cells of the canal-wall, 

 which here, of course, cease abruptly. 



Below the margin there is a thick layer of connective tissue, as is usually 

 the case, but in Maoridrili(s it comes right up to the marginal cells, and, 

 tapering downwards, gives the nephrostome a resemblance to an oi'dinary 

 iilass funnel, or, with its funnel-duct, to a convolvulus. 





Fig. 8. — Outline of a funnel, from the side, as seen in a living nephridiuni. The long 

 cilia were moving rapidly, and some of the cilia of the marginal cells, together 

 with those of the central cell, were sweeping strongly down the funnel.* 



Fig. 4. — Longitudinal section through a funnel, showing the nephrostomial duct passing 

 through the septum. The slowly tapering character of the funnel-duct is 

 well seen ; it joins the nephrostomial duct at the point z, and the latter 

 enters the nephridial folds at the point y. 



Fig. 5. — Transverse section of a funnel from front to back. The cilia of the central 

 cell are directed against the front wall of the funnel. 



This connective tissue is variably developed : in some funnels 1 hnd 

 that it is continued down the sides of the preseptal canal much farther 

 than in other cases ; in the section figured (fig. 4) it was feebly developed. 



The dorsal lip contains very little connective tissue, but the lower 

 lip is Supported by a considerable amount. The nuclei (as has recently 

 been described by Rosen (23) for LinnhricNs) are here crowded, and in 

 consequence this part of the funnel appears denser than the upper lip, 

 which is composed only of the central cell (fig. 4). 



In this figure the central cell, described in Lttiiihricas for the first time 

 by Benham (10), and subsequently recorded in the funnels of other earth- 



* For list of abbreviations used in this and subsequent figures sea end of 

 article, p. 100. 



