ZooL— Vol. II.] RISEN— OLIGOCHMTA. I2Q 



Nefhridia. — The anterior nephridia do not possess any 

 coelomic mantles. The posterior nephridia are partly cov- 

 ered by such mantles, the latter being divided in two lobes. 

 One of these lobes is more ventral, consisting of very large 

 cells of a radiating arrangement, the other and more dorsal 

 lobe is much larger, and consists of smaller cells which 

 contain minute opaque globular granules. The lobes are 

 long, narrow and bent backwards. The whole nephridium 

 has the shape of a figure 5. Nephropores in line with and 

 in front of setae d. 



Alimentary Canal. — The prostomial lips are small but 

 well defined. The mouth is narrow and may be said to 

 correspond to somites I and II. In line with somite III 

 there is a circular lip, much folded and composed of broad 

 clear epithelial cells, somewhat like the area of taste-cells 

 in Benhamia. The pharynx is developed only dorsally. 

 It is very short and its superposed glands are very small 

 and compressed, with their narrow ends projecting for- 

 wards. It does not occupy the whole of somite IV but 

 leaves a place for a short piece of the oesophagus at its pos- 

 terior end. The oesophagus turns upwards and occupies 

 one-half of IV and V. The gizza^'ds (fig. 56) are in VI 

 and VII; they are very minute, but still perfectly differen- 

 tiated. The one in VI is a little larger and occupies about 

 one-half of the diameter of the somite. Its muscular layer is 

 slightly wider than the epithelial layer of the intestine. The 

 gizzard in VII is longer and narrower than the anterior 

 one. Its muscular layer tapers gradually towards the septa, 

 and the thickest part of the layer does not extend over 

 one-third of the length of the somite. The gizzards are so 

 narrow that they cannot be distinguished except through 

 sections. They are not wider than the intestine and rather 

 narrower than the oesophagus in V. The tubular intestine 

 may be said to extend from VIII to XII. It tapers gradu- 

 ally towards the sacculated intestine, which commences in 

 XIII. At the entrance to the sacculated intestine it is 

 furnished with the usual large epithelial folds projecting 

 backwards. « 



