1122 OR. J. STEPHENSON ON THE OLIGOCH^TA OF THE 



Setae encliytrseiue in form ; tliere may, however, be a hint of a 

 distal curve. In some bundles the inner setas are smaller and 

 slenderer than those at the ends of the bundle [Fridericia 

 ari'augement). In front of the clitellum the ventral bundles 

 contain 4 or 5 setae, occasionally 3 ; the lateral bundles have 

 3 or 4. Behind the clitellum the ventral bundles have 4 or 5, 

 O3casionally 3 or 6 setiB ; the lateral 4, 5, or 6, occasionally 3, or 

 in the last segments even two. 



The clitellum roughly covers segm's. xii. and xiii. ; but in a 

 specimen with fully developed sexual organs one-third of xi. was 

 included, and a small portion of the hinder end of xiii. (about a 

 quarter) was free. 



A taste-organ is present on the floor of the pharynx, in front 

 of the level of the dorsal pharyngeal mass and of furrow 2/3. It 

 is best seen in longitudinal sections, according to which it is a 

 solid transverse ridge, bent somewhat forwards, with a narrow 

 free edge. Its base- is slightly narrowed (antero-posteriorly, as 

 seen in longitudinal sections), and its total height is about five 

 times the antei'o-posterior thickness of its base of attachment. It 

 is composed of eloiigated cells, and being solid is distinguishable 

 from the other ridges of the ventral pharyngeal wall, which are 

 merely folds of the epithelium. In one specimen the pharjaix is 

 being everted; it is the ventral wall alone that comes forward 

 here, and the taste-organ is at the tip of the everted pai't, so 

 that it comes just onto a level with the mouth-opening, or 

 in one or two sections rather farther, projecting a little from 

 the mouth. Some deeply staining matter is apparently being 

 ta,ken in. 



The septal glands are bulky ; the last is in relation with 

 septum 6/7, covering both sides of it and thus occupying part of 

 segm. vii. 



There are dorsal and ventral oesophageal nephridia. The dorsal 

 organ ends behind in segm. vi., and gives a branch dorsalwards 

 just in front of its ending; in front it gets into segm. v. in one 

 series of sections, and ends some dista,nce above the cesopha,gus 

 a,nd not in contact with it. In another specimen, cut into longi- 

 tudinal sections, it is confined to vi., and appears a,s a projecting 

 mass dorsally on the oesophagus, spongy in texture, hardly 

 staining, irregular in shape, and in intimate connection with the 

 dorsal vessel ; indeed, a proper wall of the dorsal vessel is wanting, 

 or cannot be distinguished, and the blood appears to be contained 

 Avithin a sinus in the nephridial tissue. 



The ventral nephridium ends behind by branching into two at 

 a level just in front of that of the end of the dorsal organ ; each 

 branch extends laterally for some distance, and then terminates 

 by turning somewhat forvv'ards. These branches form the chief 

 part of the organ ; the median portion, on the ventral oesophageal 

 wall, is soon lost, and does not seem to get forwards into segm. v. 

 This nephridium also is in close relation with blood-spaces — in 

 this case those of the alimentary wall (text-fig. 1). 



