NOTES ON ESSEX WORMS (OLIGOCHAETA). 111
segment, and are simple diverticula. My figures show them in
segment seven, highly developed. It would be interesting to obtain
fresh material for a fuller comparison with the newest account.
Perhaps some collector will be good' enough to look out for this
species, and forward them to me for the purpose.
II.—Dichaeta curvisetosa, Nov. sp. et. Gen.
Some time ago I received from Dr. Wheeler, of Chelmsford, a
solitary specimen of a Freshwater Worm preserved in glycerine,
which presented so many unusual features that I hesitated to publish
an account of the same on the strength of a solitary specimen. Now
that Mr. Beddard's work has been published, however, I feel that it
is due to other workers in this field that I should state the facts.
The worm was four inches in length, of a very lively nature
when first discovered, and having all the appearance (from its great
fineness and length) of a moving hair or living thread. I was
instantly struck by the fact that it possessed setae on the very first
segment. This was a totally new feature ; but I find that Schmarda
has figured another species with the same peculiarity. Then I
observed that there were no dorsal seta;, and the ventral bundles had
been reduced to their lowest possible limit—the result being the
unique number of two setae on each segment. The head was long
and narrow, and from this and the other characters I conclude that
it is a new genus belonging to the Chaetogaster group. As it was
necessary to suggest some name by means of which the worm can in
future be discussed, I have fixed upon the bisetose character for the
generic name, and called it Dichaeta, quite a different term from the
well-established Diachaeta. I regret that I have never been able to
obtain a duplicate, and hope that this note may lead some one
living in Chelmsford to make careful search for further specimens.
7, Fern Bank, Cockermouth, January 3rd, 1896.
3 See Essex Naturalist, vol. vi., p. 189.