120 Journal of the Asiatic Society of Bengal. [April, 1905. 
between them and the original ones. When several have been 
produced, the most anterior can be distinguished from the others 
by a dilatation of the alimentary canal which ultimately becomes 
the pharynx of a new individual. The prostomium never takes 
its place as a regular segment in the series, but grows out as a 
lobe on the dorsal surface. The mouth of the young worm is in 
ity of the young individual, until the separation has been com- 
pletely affected. This does not occur until at least 16 new seg- 
0eer- 
EXPLANATION OF PLATE III. 
Fig. 1. Cheetogaster bengalensis on a Water-Snail, X 2. 
» 2. Anterior extremity of an adult individual from below, 
showing nerve cords, ete. (Much enlarged). 
p.—prostomium, 1.—lower lip, s,—anterior sete, ™— 
nerve chords, g.—ganglia. 
» 3% Diagram showing arrangement of the sete in a similar 
bundle from the right side. Each dot represents @ seta 
1n cross-section. 5 
» 4. A bundle of sete from the left side of one of the posterior 
segments, seen from behind. (Much enlarged). 
(Text figure.) : 
Fig. 1. Young Ohxtogaster bengalensis just separated by ere 
from its parent. (Somewhat diagrammatic as reg@ 
a). : 
p-—prostomium, ph.—pharynx, 1.ph.—lumen of pha 
rynx 
e.—cesophagus, c.—clitellum, n,—nephridia, 
p-8.— posterior sucker. ; 
