PACIFIC COAST OLIGOCH MTA, 69 
a. Nephrostomal part. 
Nephrostome, or funnel. 
Neck of nephrostome, consisting of glandular cells. 
Narrow, or nephrostomal duct. 
b. Main glandular part. 
Neck of glandular lobe, connected with the nephrostomal duct. 
Anterior fold. 
The windings, or the coiled part of the two folds. 
Posterior fold, in which the three canals are of the same size. 
Spur, with four canals. 
Bridge, with only one canal. 
c. Efferent part. 
Wide terminal-duct or outlet. The latter is frequently furnished with a 
ceelomic bladder. 
Nephropore. 
When the nephridium is spread out and mounted in glycerine it is seen that 
the canals are of different transparency. Thus the wide canal coming from the bridge, 
together with its continuation in the spur, is much darker than the two other narrow 
canals, which are conspicuous through their brillianey. These two white canals meet 
in the very apex of the spur, while the two darker canals meet a little further in. 
The greater obscurity of the wider canal is partly due to ciliation. 
The nephrostome of Phwnicodrilus taste is furnished with a large neck, almost 
as large as the rosette, containing several very large cells with conspicuous nuclei. 
The nephrostome is about as Jong as the narrow tube. 
In size the nephrostome ranges with the very largest, it being conspicuous 
and readily dissected. 
The marginal cells vary in number between eight and fourteen. There is a 
larger central nucleus as usual. The glandular neck of the nephrostome contains 
two of these nuclei much larger than any of those found in the rosette, though it also 
contains several smaller ones. When the body of the annelid is laid open and viewed 
from above, the nephrostomes are seen to lie on their side as in fig. 9, the side of 
the thick rim of the rosette being uppermost. In order to see the rosette flattened 
out it is necessary to dissect out the nephrostome, which operation in this species is 
not particularly difficult, as the muscular tissues easily separate. 
The peritoneal covering of the posterior nephridia separates itself in two dis- 
tinct masses, one dorsal and one ventral, the latter being somewhat the smallest. At 
the point where they join the peritoneal covering has narrowed down to a narrow 
band connecting the two main parts. 
The upper peritoneal mass does not surround or contain any of the canals or 
ducts, but appears to be merely an appendage, a gland, as it were, engrafted on the 
lower part. The canals and tubes are entirely confined to this part, as is also the case 
in the nephridia of Ocnerodrilus and Kerria. 
