NEW BRITISH OLIGOCHATS. 225 
description :—Length, 10-12 mm., transparent, almost white to 
the naked eye. Brain not incised behind as is frequently the 
case, but rounded, one and a half times longer than broad. Long, 
unbranched salivary glands, resembling those of Enchytreus pel- 
lucidus, Friend. Sete 2-4 in front, hooked within. Cclomic 
corpuscles large, oval, nucleated, clear or light brown. Nephridia 
brown ; large postseptal, with duct short, and apparently rising 
near the posterior extremity. Dorsal vessel rises in 44, where 
the intestine enlarges, pulsing. Chloragogen-cells warm brown. 
Funnel of sperm-duct narrow, somewhat long, and usually 
curved round, so that the length cannot be accurately judged ; 
estimated at four times longer than broad. Duct of the sperma- 
theca about as long as the ampulla, which is pear-shaped. 
This species seems to be a link with Hnchytreus. The sali- 
varies, sete, spermathece, rounded brain, and almost or quite 
colourless blood are all Enchytreus-like, yet the whole worm is 
decidedly Marionina-like. These discoveries show the difficulties 
of the systematist in drawing the line between the different 
genera. Along with the foregoing I found another and a smaller 
species, which agrees with none of the descriptions which I have 
been able to consult. I therefore proceed to its description. 
9. MARIONINA GLANDIFERA, n. Sp.—Length about 8 mm., with 
36 segments. Of a pinkish white colour. Sete usually 5 in 
front (rarely 4 or 6), about equal in length ; from 3 to 5 behind. 
A small delicate worm, but very active, in which it differs much 
from the last, though found in the same habitat. Spermatheca 
long, oval or elliptical sacs, without distinction of duct and 
ampulla; attached to cesophagus, and in February full of 
spermatozoa. The spermathece often assume an s-shape when 
at rest. The body is glandular all over, the clear glanas being 
in transverse rows, often as many as fifteen in number behind 
the girdle in each segment. Ccelomic corpuscles large, brown, 
numerous, somewhat oval discs. Glands of girdle fairly large, 
with correspondingly large open spaces. Here also we find large 
pores and glands, a duct which extends back as far as segment 
16, with ampulla about two or three times longer than broad. 
There are a few chloragogen-cells in 5, the full number in 6, 7, 8, 
then few or none until the girdle segment is passed. There are 
usually three setz in the dorsal bundles of the girdle. Three 
