NERILLA AN ARCH I ANNELID. 
405 
just as they do in Protodrilus according to Pierantoni ( 14 ). 
A few of these cells may sometimes be found scattered on 
the anterior wall of the oesophagus, and some may open 
independently into its lumen. Salivary glands quite similar 
in structure and staining properties have been described by 
Nelson in Dinophilus conklini ( 18 ). 
The limit between the oesophagus and the stomacli is 
generally marked by a circular fold ; the limit between the 
stomach and intestine is still more definitely shown by a 
pyloric thickening of the wall surrounding the lumen in the 
sixth segment (fig. 1). Running along on each side of the 
stomach wall is a band of gland-cells, very conspicuous in 
section owing to the great avidity for stains of the granules 
which fill them (figs. 13, 21). The glandular band begins a 
little way behind the front end of the stomach, reaches its 
greatest development about half-way down, and dies away 
again before the pylorus. The cells which compose it open 
independently into the cavity of the stomach, passing between 
the ordinary ciliated epithelial cells. Their swollen bodies, 
full of granules, bulge outwards on to the surface of the 
epithelium, giving the wall of the gut the appearance of 
being formed of more than one layer (fig. 13). Quite similar 
cells scattered in the wall of the stomach have been described 
by Nelson in Dinophilus ( 18 ). Strangely enough, Miss 
Pereyaslawzewa mistook these gland-cells for developing 
germ-cells in both sexes ( 13 ). A ventral groove runs along 
the intestine, due to a slight folding of the floor, and along 
it the cilia, at all events at times, work forwards, as is so 
ofyen the case in Syllids. Immediately in front of the anus 
there is a quite short rectal region with thick ventral wall ; 
presumably it represents the proctodaeum. 
The C(elom and General Mesoblastic Tissues. 
There is a clearly defined body-cavity having all the 
essential characters of a coelom. The coelom of the first 
segment extends into the prostomium : it is closed off by a 
