new Aquatic Annelids. 139 
prominent, at least in the spring, and the grooves between 
the segments are usually quite distinct. A deep groove 
traverses the dorsal surface of the worm, exactly as described 
by Benham for the Thames species, when placed in alcohol. 
I observed, however, that those which were preserved in weak 
formaldehyde retained the cylindrical form unchanged. 
The most anterior nephridia vary in position, and seem to 
commence, sometimes in segment 12, at others in 13 or 14, 
the postseptal being limited to the next segment behind 
Fig. 3. 
Sparganophilus elongatus. Young seta. Enlarged. 
these. The nephridiopores are immediately in front of the 
ventralmost sete, instead of in the mid-line between the 
ventral pair. 
Internally the structure agrees in the main with Sp. tamesis. 
There are, however, well-marked dilatations in segments 15 
to 18, as well as in the vascular system of 9,10,and11. The 
ventral vessel is much branched in the fifteenth and sixteenth 
segments, ‘lhe cesophagus is distinctly modified in the 
eighth and ninth segments. There are no cesophageal 
glands, but in segment 3 are certain bodies which may be 
compared with the coelomic glands of Sp. eisent, Smith. 
They have not been recorded hitherto for either Sp. benhami 
or Sp. tamesis. 
2. Anagaster fontinalis, gen. et sp. n. 
While residing in Suffolk in 1907 I found some new well- 
worms at Mildenhall. There seem to have been two species, 
one of which was, in all probability, a Haplotawxis related to 
or identical with that found in Cambridge by Beddard 
(Phreatothriz cantabrigiensis, Bedd.). The other appears to 
me to be not only a new species, but also a new genus, and 
the first indisputable member of the Criodrilinw, of indige- 
nous habit, yet found in this country. 
The length of A. fontinalis is about 2 inches, the number 
of segments 100. ‘Ihe male pores are in front of the girdle 
on segment 15 as in Criodrilus, and not within the 
girdle limits as in Sparganophilus. Vhe girdle commences 
